1------------------------------------------------------------------------------ 2-- -- 3-- GNAT COMPILER COMPONENTS -- 4-- -- 5-- G N A T . P E R F E C T _ H A S H _ G E N E R A T O R S -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 2002-2018, AdaCore -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNAT was originally developed by the GNAT team at New York University. -- 28-- Extensive contributions were provided by Ada Core Technologies Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32with Ada.IO_Exceptions; use Ada.IO_Exceptions; 33with Ada.Characters.Handling; use Ada.Characters.Handling; 34with Ada.Directories; 35 36with GNAT.Heap_Sort_G; 37with GNAT.OS_Lib; use GNAT.OS_Lib; 38with GNAT.Table; 39 40package body GNAT.Perfect_Hash_Generators is 41 42 -- We are using the algorithm of J. Czech as described in Zbigniew J. 43 -- Czech, George Havas, and Bohdan S. Majewski ``An Optimal Algorithm for 44 -- Generating Minimal Perfect Hash Functions'', Information Processing 45 -- Letters, 43(1992) pp.257-264, Oct.1992 46 47 -- This minimal perfect hash function generator is based on random graphs 48 -- and produces a hash function of the form: 49 50 -- h (w) = (g (f1 (w)) + g (f2 (w))) mod m 51 52 -- where f1 and f2 are functions that map strings into integers, and g is 53 -- a function that maps integers into [0, m-1]. h can be order preserving. 54 -- For instance, let W = {w_0, ..., w_i, ..., w_m-1}, h can be defined 55 -- such that h (w_i) = i. 56 57 -- This algorithm defines two possible constructions of f1 and f2. Method 58 -- b) stores the hash function in less memory space at the expense of 59 -- greater CPU time. 60 61 -- a) fk (w) = sum (for i in 1 .. length (w)) (Tk (i, w (i))) mod n 62 63 -- size (Tk) = max (for w in W) (length (w)) * size (used char set) 64 65 -- b) fk (w) = sum (for i in 1 .. length (w)) (Tk (i) * w (i)) mod n 66 67 -- size (Tk) = max (for w in W) (length (w)) but the table lookups are 68 -- replaced by multiplications. 69 70 -- where Tk values are randomly generated. n is defined later on but the 71 -- algorithm recommends to use a value a little bit greater than 2m. Note 72 -- that for large values of m, the main memory space requirements comes 73 -- from the memory space for storing function g (>= 2m entries). 74 75 -- Random graphs are frequently used to solve difficult problems that do 76 -- not have polynomial solutions. This algorithm is based on a weighted 77 -- undirected graph. It comprises two steps: mapping and assignment. 78 79 -- In the mapping step, a graph G = (V, E) is constructed, where = {0, 1, 80 -- ..., n-1} and E = {(for w in W) (f1 (w), f2 (w))}. In order for the 81 -- assignment step to be successful, G has to be acyclic. To have a high 82 -- probability of generating an acyclic graph, n >= 2m. If it is not 83 -- acyclic, Tk have to be regenerated. 84 85 -- In the assignment step, the algorithm builds function g. As G is 86 -- acyclic, there is a vertex v1 with only one neighbor v2. Let w_i be 87 -- the word such that v1 = f1 (w_i) and v2 = f2 (w_i). Let g (v1) = 0 by 88 -- construction and g (v2) = (i - g (v1)) mod n (or h (i) - g (v1) mod n). 89 -- If word w_j is such that v2 = f1 (w_j) and v3 = f2 (w_j), g (v3) = (j - 90 -- g (v2)) mod (or to be general, (h (j) - g (v2)) mod n). If w_i has no 91 -- neighbor, then another vertex is selected. The algorithm traverses G to 92 -- assign values to all the vertices. It cannot assign a value to an 93 -- already assigned vertex as G is acyclic. 94 95 subtype Word_Id is Integer; 96 subtype Key_Id is Integer; 97 subtype Vertex_Id is Integer; 98 subtype Edge_Id is Integer; 99 subtype Table_Id is Integer; 100 101 No_Vertex : constant Vertex_Id := -1; 102 No_Edge : constant Edge_Id := -1; 103 No_Table : constant Table_Id := -1; 104 105 type Word_Type is new String_Access; 106 procedure Free_Word (W : in out Word_Type) renames Free; 107 function New_Word (S : String) return Word_Type; 108 109 procedure Resize_Word (W : in out Word_Type; Len : Natural); 110 -- Resize string W to have a length Len 111 112 type Key_Type is record 113 Edge : Edge_Id; 114 end record; 115 -- A key corresponds to an edge in the algorithm graph 116 117 type Vertex_Type is record 118 First : Edge_Id; 119 Last : Edge_Id; 120 end record; 121 -- A vertex can be involved in several edges. First and Last are the bounds 122 -- of an array of edges stored in a global edge table. 123 124 type Edge_Type is record 125 X : Vertex_Id; 126 Y : Vertex_Id; 127 Key : Key_Id; 128 end record; 129 -- An edge is a peer of vertices. In the algorithm, a key is associated to 130 -- an edge. 131 132 package WT is new GNAT.Table (Word_Type, Word_Id, 0, 32, 32); 133 package IT is new GNAT.Table (Integer, Integer, 0, 32, 32); 134 -- The two main tables. WT is used to store the words in their initial 135 -- version and in their reduced version (that is words reduced to their 136 -- significant characters). As an instance of GNAT.Table, WT does not 137 -- initialize string pointers to null. This initialization has to be done 138 -- manually when the table is allocated. IT is used to store several 139 -- tables of components containing only integers. 140 141 function Image (Int : Integer; W : Natural := 0) return String; 142 function Image (Str : String; W : Natural := 0) return String; 143 -- Return a string which includes string Str or integer Int preceded by 144 -- leading spaces if required by width W. 145 146 function Trim_Trailing_Nuls (Str : String) return String; 147 -- Return Str with trailing NUL characters removed 148 149 Output : File_Descriptor renames GNAT.OS_Lib.Standout; 150 -- Shortcuts 151 152 EOL : constant Character := ASCII.LF; 153 154 Max : constant := 78; 155 Last : Natural := 0; 156 Line : String (1 .. Max); 157 -- Use this line to provide buffered IO 158 159 procedure Add (C : Character); 160 procedure Add (S : String); 161 -- Add a character or a string in Line and update Last 162 163 procedure Put 164 (F : File_Descriptor; 165 S : String; 166 F1 : Natural; 167 L1 : Natural; 168 C1 : Natural; 169 F2 : Natural; 170 L2 : Natural; 171 C2 : Natural); 172 -- Write string S into file F as a element of an array of one or two 173 -- dimensions. Fk (resp. Lk and Ck) indicates the first (resp last and 174 -- current) index in the k-th dimension. If F1 = L1 the array is considered 175 -- as a one dimension array. This dimension is described by F2 and L2. This 176 -- routine takes care of all the parenthesis, spaces and commas needed to 177 -- format correctly the array. Moreover, the array is well indented and is 178 -- wrapped to fit in a 80 col line. When the line is full, the routine 179 -- writes it into file F. When the array is completed, the routine adds 180 -- semi-colon and writes the line into file F. 181 182 procedure New_Line (File : File_Descriptor); 183 -- Simulate Ada.Text_IO.New_Line with GNAT.OS_Lib 184 185 procedure Put (File : File_Descriptor; Str : String); 186 -- Simulate Ada.Text_IO.Put with GNAT.OS_Lib 187 188 procedure Put_Used_Char_Set (File : File_Descriptor; Title : String); 189 -- Output a title and a used character set 190 191 procedure Put_Int_Vector 192 (File : File_Descriptor; 193 Title : String; 194 Vector : Integer; 195 Length : Natural); 196 -- Output a title and a vector 197 198 procedure Put_Int_Matrix 199 (File : File_Descriptor; 200 Title : String; 201 Table : Table_Id; 202 Len_1 : Natural; 203 Len_2 : Natural); 204 -- Output a title and a matrix. When the matrix has only one non-empty 205 -- dimension (Len_2 = 0), output a vector. 206 207 procedure Put_Edges (File : File_Descriptor; Title : String); 208 -- Output a title and an edge table 209 210 procedure Put_Initial_Keys (File : File_Descriptor; Title : String); 211 -- Output a title and a key table 212 213 procedure Put_Reduced_Keys (File : File_Descriptor; Title : String); 214 -- Output a title and a key table 215 216 procedure Put_Vertex_Table (File : File_Descriptor; Title : String); 217 -- Output a title and a vertex table 218 219 function Ada_File_Base_Name (Pkg_Name : String) return String; 220 -- Return the base file name (i.e. without .ads/.adb extension) for an 221 -- Ada source file containing the named package, using the standard GNAT 222 -- file-naming convention. For example, if Pkg_Name is "Parent.Child", we 223 -- return "parent-child". 224 225 ---------------------------------- 226 -- Character Position Selection -- 227 ---------------------------------- 228 229 -- We reduce the maximum key size by selecting representative positions 230 -- in these keys. We build a matrix with one word per line. We fill the 231 -- remaining space of a line with ASCII.NUL. The heuristic selects the 232 -- position that induces the minimum number of collisions. If there are 233 -- collisions, select another position on the reduced key set responsible 234 -- of the collisions. Apply the heuristic until there is no more collision. 235 236 procedure Apply_Position_Selection; 237 -- Apply Position selection and build the reduced key table 238 239 procedure Parse_Position_Selection (Argument : String); 240 -- Parse Argument and compute the position set. Argument is list of 241 -- substrings separated by commas. Each substring represents a position 242 -- or a range of positions (like x-y). 243 244 procedure Select_Character_Set; 245 -- Define an optimized used character set like Character'Pos in order not 246 -- to allocate tables of 256 entries. 247 248 procedure Select_Char_Position; 249 -- Find a min char position set in order to reduce the max key length. The 250 -- heuristic selects the position that induces the minimum number of 251 -- collisions. If there are collisions, select another position on the 252 -- reduced key set responsible of the collisions. Apply the heuristic until 253 -- there is no collision. 254 255 ----------------------------- 256 -- Random Graph Generation -- 257 ----------------------------- 258 259 procedure Random (Seed : in out Natural); 260 -- Simulate Ada.Discrete_Numerics.Random 261 262 procedure Generate_Mapping_Table 263 (Tab : Table_Id; 264 L1 : Natural; 265 L2 : Natural; 266 Seed : in out Natural); 267 -- Random generation of the tables below. T is already allocated 268 269 procedure Generate_Mapping_Tables 270 (Opt : Optimization; 271 Seed : in out Natural); 272 -- Generate the mapping tables T1 and T2. They are used to define fk (w) = 273 -- sum (for i in 1 .. length (w)) (Tk (i, w (i))) mod n. Keys, NK and Chars 274 -- are used to compute the matrix size. 275 276 --------------------------- 277 -- Algorithm Computation -- 278 --------------------------- 279 280 procedure Compute_Edges_And_Vertices (Opt : Optimization); 281 -- Compute the edge and vertex tables. These are empty when a self loop is 282 -- detected (f1 (w) = f2 (w)). The edge table is sorted by X value and then 283 -- Y value. Keys is the key table and NK the number of keys. Chars is the 284 -- set of characters really used in Keys. NV is the number of vertices 285 -- recommended by the algorithm. T1 and T2 are the mapping tables needed to 286 -- compute f1 (w) and f2 (w). 287 288 function Acyclic return Boolean; 289 -- Return True when the graph is acyclic. Vertices is the current vertex 290 -- table and Edges the current edge table. 291 292 procedure Assign_Values_To_Vertices; 293 -- Execute the assignment step of the algorithm. Keys is the current key 294 -- table. Vertices and Edges represent the random graph. G is the result of 295 -- the assignment step such that: 296 -- h (w) = (g (f1 (w)) + g (f2 (w))) mod m 297 298 function Sum 299 (Word : Word_Type; 300 Table : Table_Id; 301 Opt : Optimization) return Natural; 302 -- For an optimization of CPU_Time return 303 -- fk (w) = sum (for i in 1 .. length (w)) (Tk (i, w (i))) mod n 304 -- For an optimization of Memory_Space return 305 -- fk (w) = sum (for i in 1 .. length (w)) (Tk (i) * w (i)) mod n 306 -- Here NV = n 307 308 ------------------------------- 309 -- Internal Table Management -- 310 ------------------------------- 311 312 function Allocate (N : Natural; S : Natural := 1) return Table_Id; 313 -- Allocate N * S ints from IT table 314 315 ---------- 316 -- Keys -- 317 ---------- 318 319 Keys : Table_Id := No_Table; 320 NK : Natural := 0; 321 -- NK : Number of Keys 322 323 function Initial (K : Key_Id) return Word_Id; 324 pragma Inline (Initial); 325 326 function Reduced (K : Key_Id) return Word_Id; 327 pragma Inline (Reduced); 328 329 function Get_Key (N : Key_Id) return Key_Type; 330 procedure Set_Key (N : Key_Id; Item : Key_Type); 331 -- Get or Set Nth element of Keys table 332 333 ------------------ 334 -- Char_Pos_Set -- 335 ------------------ 336 337 Char_Pos_Set : Table_Id := No_Table; 338 Char_Pos_Set_Len : Natural; 339 -- Character Selected Position Set 340 341 function Get_Char_Pos (P : Natural) return Natural; 342 procedure Set_Char_Pos (P : Natural; Item : Natural); 343 -- Get or Set the string position of the Pth selected character 344 345 ------------------- 346 -- Used_Char_Set -- 347 ------------------- 348 349 Used_Char_Set : Table_Id := No_Table; 350 Used_Char_Set_Len : Natural; 351 -- Used Character Set : Define a new character mapping. When all the 352 -- characters are not present in the keys, in order to reduce the size 353 -- of some tables, we redefine the character mapping. 354 355 function Get_Used_Char (C : Character) return Natural; 356 procedure Set_Used_Char (C : Character; Item : Natural); 357 358 ------------ 359 -- Tables -- 360 ------------ 361 362 T1 : Table_Id := No_Table; 363 T2 : Table_Id := No_Table; 364 T1_Len : Natural; 365 T2_Len : Natural; 366 -- T1 : Values table to compute F1 367 -- T2 : Values table to compute F2 368 369 function Get_Table (T : Integer; X, Y : Natural) return Natural; 370 procedure Set_Table (T : Integer; X, Y : Natural; Item : Natural); 371 372 ----------- 373 -- Graph -- 374 ----------- 375 376 G : Table_Id := No_Table; 377 G_Len : Natural; 378 -- Values table to compute G 379 380 NT : Natural := Default_Tries; 381 -- Number of tries running the algorithm before raising an error 382 383 function Get_Graph (N : Natural) return Integer; 384 procedure Set_Graph (N : Natural; Item : Integer); 385 -- Get or Set Nth element of graph 386 387 ----------- 388 -- Edges -- 389 ----------- 390 391 Edge_Size : constant := 3; 392 Edges : Table_Id := No_Table; 393 Edges_Len : Natural; 394 -- Edges : Edge table of the random graph G 395 396 function Get_Edges (F : Natural) return Edge_Type; 397 procedure Set_Edges (F : Natural; Item : Edge_Type); 398 399 -------------- 400 -- Vertices -- 401 -------------- 402 403 Vertex_Size : constant := 2; 404 405 Vertices : Table_Id := No_Table; 406 -- Vertex table of the random graph G 407 408 NV : Natural; 409 -- Number of Vertices 410 411 function Get_Vertices (F : Natural) return Vertex_Type; 412 procedure Set_Vertices (F : Natural; Item : Vertex_Type); 413 -- Comments needed ??? 414 415 K2V : Float; 416 -- Ratio between Keys and Vertices (parameter of Czech's algorithm) 417 418 Opt : Optimization; 419 -- Optimization mode (memory vs CPU) 420 421 Max_Key_Len : Natural := 0; 422 Min_Key_Len : Natural := 0; 423 -- Maximum and minimum of all the word length 424 425 S : Natural; 426 -- Seed 427 428 function Type_Size (L : Natural) return Natural; 429 -- Given the last L of an unsigned integer type T, return its size 430 431 ------------- 432 -- Acyclic -- 433 ------------- 434 435 function Acyclic return Boolean is 436 Marks : array (0 .. NV - 1) of Vertex_Id := (others => No_Vertex); 437 438 function Traverse (Edge : Edge_Id; Mark : Vertex_Id) return Boolean; 439 -- Propagate Mark from X to Y. X is already marked. Mark Y and propagate 440 -- it to the edges of Y except the one representing the same key. Return 441 -- False when Y is marked with Mark. 442 443 -------------- 444 -- Traverse -- 445 -------------- 446 447 function Traverse (Edge : Edge_Id; Mark : Vertex_Id) return Boolean is 448 E : constant Edge_Type := Get_Edges (Edge); 449 K : constant Key_Id := E.Key; 450 Y : constant Vertex_Id := E.Y; 451 M : constant Vertex_Id := Marks (E.Y); 452 V : Vertex_Type; 453 454 begin 455 if M = Mark then 456 return False; 457 458 elsif M = No_Vertex then 459 Marks (Y) := Mark; 460 V := Get_Vertices (Y); 461 462 for J in V.First .. V.Last loop 463 464 -- Do not propagate to the edge representing the same key 465 466 if Get_Edges (J).Key /= K 467 and then not Traverse (J, Mark) 468 then 469 return False; 470 end if; 471 end loop; 472 end if; 473 474 return True; 475 end Traverse; 476 477 Edge : Edge_Type; 478 479 -- Start of processing for Acyclic 480 481 begin 482 -- Edges valid range is 483 484 for J in 1 .. Edges_Len - 1 loop 485 486 Edge := Get_Edges (J); 487 488 -- Mark X of E when it has not been already done 489 490 if Marks (Edge.X) = No_Vertex then 491 Marks (Edge.X) := Edge.X; 492 end if; 493 494 -- Traverse E when this has not already been done 495 496 if Marks (Edge.Y) = No_Vertex 497 and then not Traverse (J, Edge.X) 498 then 499 return False; 500 end if; 501 end loop; 502 503 return True; 504 end Acyclic; 505 506 ------------------------ 507 -- Ada_File_Base_Name -- 508 ------------------------ 509 510 function Ada_File_Base_Name (Pkg_Name : String) return String is 511 begin 512 -- Convert to lower case, then replace '.' with '-' 513 514 return Result : String := To_Lower (Pkg_Name) do 515 for J in Result'Range loop 516 if Result (J) = '.' then 517 Result (J) := '-'; 518 end if; 519 end loop; 520 end return; 521 end Ada_File_Base_Name; 522 523 --------- 524 -- Add -- 525 --------- 526 527 procedure Add (C : Character) is 528 pragma Assert (C /= ASCII.NUL); 529 begin 530 Line (Last + 1) := C; 531 Last := Last + 1; 532 end Add; 533 534 --------- 535 -- Add -- 536 --------- 537 538 procedure Add (S : String) is 539 Len : constant Natural := S'Length; 540 begin 541 for J in S'Range loop 542 pragma Assert (S (J) /= ASCII.NUL); 543 null; 544 end loop; 545 546 Line (Last + 1 .. Last + Len) := S; 547 Last := Last + Len; 548 end Add; 549 550 -------------- 551 -- Allocate -- 552 -------------- 553 554 function Allocate (N : Natural; S : Natural := 1) return Table_Id is 555 L : constant Integer := IT.Last; 556 begin 557 IT.Set_Last (L + N * S); 558 559 -- Initialize, so debugging printouts don't trip over uninitialized 560 -- components. 561 562 for J in L + 1 .. IT.Last loop 563 IT.Table (J) := -1; 564 end loop; 565 566 return L + 1; 567 end Allocate; 568 569 ------------------------------ 570 -- Apply_Position_Selection -- 571 ------------------------------ 572 573 procedure Apply_Position_Selection is 574 begin 575 for J in 0 .. NK - 1 loop 576 declare 577 IW : constant String := WT.Table (Initial (J)).all; 578 RW : String (1 .. IW'Length) := (others => ASCII.NUL); 579 N : Natural := IW'First - 1; 580 581 begin 582 -- Select the characters of Word included in the position 583 -- selection. 584 585 for C in 0 .. Char_Pos_Set_Len - 1 loop 586 exit when IW (Get_Char_Pos (C)) = ASCII.NUL; 587 N := N + 1; 588 RW (N) := IW (Get_Char_Pos (C)); 589 end loop; 590 591 -- Build the new table with the reduced word. Be careful 592 -- to deallocate the old version to avoid memory leaks. 593 594 Free_Word (WT.Table (Reduced (J))); 595 WT.Table (Reduced (J)) := New_Word (RW); 596 Set_Key (J, (Edge => No_Edge)); 597 end; 598 end loop; 599 end Apply_Position_Selection; 600 601 ------------------------------- 602 -- Assign_Values_To_Vertices -- 603 ------------------------------- 604 605 procedure Assign_Values_To_Vertices is 606 X : Vertex_Id; 607 608 procedure Assign (X : Vertex_Id); 609 -- Execute assignment on X's neighbors except the vertex that we are 610 -- coming from which is already assigned. 611 612 ------------ 613 -- Assign -- 614 ------------ 615 616 procedure Assign (X : Vertex_Id) is 617 E : Edge_Type; 618 V : constant Vertex_Type := Get_Vertices (X); 619 620 begin 621 for J in V.First .. V.Last loop 622 E := Get_Edges (J); 623 624 if Get_Graph (E.Y) = -1 then 625 Set_Graph (E.Y, (E.Key - Get_Graph (X)) mod NK); 626 Assign (E.Y); 627 end if; 628 end loop; 629 end Assign; 630 631 -- Start of processing for Assign_Values_To_Vertices 632 633 begin 634 -- Value -1 denotes an uninitialized value as it is supposed to 635 -- be in the range 0 .. NK. 636 637 if G = No_Table then 638 G_Len := NV; 639 G := Allocate (G_Len, 1); 640 end if; 641 642 for J in 0 .. G_Len - 1 loop 643 Set_Graph (J, -1); 644 end loop; 645 646 for K in 0 .. NK - 1 loop 647 X := Get_Edges (Get_Key (K).Edge).X; 648 649 if Get_Graph (X) = -1 then 650 Set_Graph (X, 0); 651 Assign (X); 652 end if; 653 end loop; 654 655 for J in 0 .. G_Len - 1 loop 656 if Get_Graph (J) = -1 then 657 Set_Graph (J, 0); 658 end if; 659 end loop; 660 661 if Verbose then 662 Put_Int_Vector (Output, "Assign Values To Vertices", G, G_Len); 663 end if; 664 end Assign_Values_To_Vertices; 665 666 ------------- 667 -- Compute -- 668 ------------- 669 670 procedure Compute (Position : String := Default_Position) is 671 Success : Boolean := False; 672 673 begin 674 if NK = 0 then 675 raise Program_Error with "keywords set cannot be empty"; 676 end if; 677 678 if Verbose then 679 Put_Initial_Keys (Output, "Initial Key Table"); 680 end if; 681 682 if Position'Length /= 0 then 683 Parse_Position_Selection (Position); 684 else 685 Select_Char_Position; 686 end if; 687 688 if Verbose then 689 Put_Int_Vector 690 (Output, "Char Position Set", Char_Pos_Set, Char_Pos_Set_Len); 691 end if; 692 693 Apply_Position_Selection; 694 695 if Verbose then 696 Put_Reduced_Keys (Output, "Reduced Keys Table"); 697 end if; 698 699 Select_Character_Set; 700 701 if Verbose then 702 Put_Used_Char_Set (Output, "Character Position Table"); 703 end if; 704 705 -- Perform Czech's algorithm 706 707 for J in 1 .. NT loop 708 Generate_Mapping_Tables (Opt, S); 709 Compute_Edges_And_Vertices (Opt); 710 711 -- When graph is not empty (no self-loop from previous operation) and 712 -- not acyclic. 713 714 if 0 < Edges_Len and then Acyclic then 715 Success := True; 716 exit; 717 end if; 718 end loop; 719 720 if not Success then 721 raise Too_Many_Tries; 722 end if; 723 724 Assign_Values_To_Vertices; 725 end Compute; 726 727 -------------------------------- 728 -- Compute_Edges_And_Vertices -- 729 -------------------------------- 730 731 procedure Compute_Edges_And_Vertices (Opt : Optimization) is 732 X : Natural; 733 Y : Natural; 734 Key : Key_Type; 735 Edge : Edge_Type; 736 Vertex : Vertex_Type; 737 Not_Acyclic : Boolean := False; 738 739 procedure Move (From : Natural; To : Natural); 740 function Lt (L, R : Natural) return Boolean; 741 -- Subprograms needed for GNAT.Heap_Sort_G 742 743 -------- 744 -- Lt -- 745 -------- 746 747 function Lt (L, R : Natural) return Boolean is 748 EL : constant Edge_Type := Get_Edges (L); 749 ER : constant Edge_Type := Get_Edges (R); 750 begin 751 return EL.X < ER.X or else (EL.X = ER.X and then EL.Y < ER.Y); 752 end Lt; 753 754 ---------- 755 -- Move -- 756 ---------- 757 758 procedure Move (From : Natural; To : Natural) is 759 begin 760 Set_Edges (To, Get_Edges (From)); 761 end Move; 762 763 package Sorting is new GNAT.Heap_Sort_G (Move, Lt); 764 765 -- Start of processing for Compute_Edges_And_Vertices 766 767 begin 768 -- We store edges from 1 to 2 * NK and leave zero alone in order to use 769 -- GNAT.Heap_Sort_G. 770 771 Edges_Len := 2 * NK + 1; 772 773 if Edges = No_Table then 774 Edges := Allocate (Edges_Len, Edge_Size); 775 end if; 776 777 if Vertices = No_Table then 778 Vertices := Allocate (NV, Vertex_Size); 779 end if; 780 781 for J in 0 .. NV - 1 loop 782 Set_Vertices (J, (No_Vertex, No_Vertex - 1)); 783 end loop; 784 785 -- For each w, X = f1 (w) and Y = f2 (w) 786 787 for J in 0 .. NK - 1 loop 788 Key := Get_Key (J); 789 Key.Edge := No_Edge; 790 Set_Key (J, Key); 791 792 X := Sum (WT.Table (Reduced (J)), T1, Opt); 793 Y := Sum (WT.Table (Reduced (J)), T2, Opt); 794 795 -- Discard T1 and T2 as soon as we discover a self loop 796 797 if X = Y then 798 Not_Acyclic := True; 799 exit; 800 end if; 801 802 -- We store (X, Y) and (Y, X) to ease assignment step 803 804 Set_Edges (2 * J + 1, (X, Y, J)); 805 Set_Edges (2 * J + 2, (Y, X, J)); 806 end loop; 807 808 -- Return an empty graph when self loop detected 809 810 if Not_Acyclic then 811 Edges_Len := 0; 812 813 else 814 if Verbose then 815 Put_Edges (Output, "Unsorted Edge Table"); 816 Put_Int_Matrix (Output, "Function Table 1", T1, 817 T1_Len, T2_Len); 818 Put_Int_Matrix (Output, "Function Table 2", T2, 819 T1_Len, T2_Len); 820 end if; 821 822 -- Enforce consistency between edges and keys. Construct Vertices and 823 -- compute the list of neighbors of a vertex First .. Last as Edges 824 -- is sorted by X and then Y. To compute the neighbor list, sort the 825 -- edges. 826 827 Sorting.Sort (Edges_Len - 1); 828 829 if Verbose then 830 Put_Edges (Output, "Sorted Edge Table"); 831 Put_Int_Matrix (Output, "Function Table 1", T1, 832 T1_Len, T2_Len); 833 Put_Int_Matrix (Output, "Function Table 2", T2, 834 T1_Len, T2_Len); 835 end if; 836 837 -- Edges valid range is 1 .. 2 * NK 838 839 for E in 1 .. Edges_Len - 1 loop 840 Edge := Get_Edges (E); 841 Key := Get_Key (Edge.Key); 842 843 if Key.Edge = No_Edge then 844 Key.Edge := E; 845 Set_Key (Edge.Key, Key); 846 end if; 847 848 Vertex := Get_Vertices (Edge.X); 849 850 if Vertex.First = No_Edge then 851 Vertex.First := E; 852 end if; 853 854 Vertex.Last := E; 855 Set_Vertices (Edge.X, Vertex); 856 end loop; 857 858 if Verbose then 859 Put_Reduced_Keys (Output, "Key Table"); 860 Put_Edges (Output, "Edge Table"); 861 Put_Vertex_Table (Output, "Vertex Table"); 862 end if; 863 end if; 864 end Compute_Edges_And_Vertices; 865 866 ------------ 867 -- Define -- 868 ------------ 869 870 procedure Define 871 (Name : Table_Name; 872 Item_Size : out Natural; 873 Length_1 : out Natural; 874 Length_2 : out Natural) 875 is 876 begin 877 case Name is 878 when Character_Position => 879 Item_Size := 8; 880 Length_1 := Char_Pos_Set_Len; 881 Length_2 := 0; 882 883 when Used_Character_Set => 884 Item_Size := 8; 885 Length_1 := 256; 886 Length_2 := 0; 887 888 when Function_Table_1 889 | Function_Table_2 890 => 891 Item_Size := Type_Size (NV); 892 Length_1 := T1_Len; 893 Length_2 := T2_Len; 894 895 when Graph_Table => 896 Item_Size := Type_Size (NK); 897 Length_1 := NV; 898 Length_2 := 0; 899 end case; 900 end Define; 901 902 -------------- 903 -- Finalize -- 904 -------------- 905 906 procedure Finalize is 907 begin 908 if Verbose then 909 Put (Output, "Finalize"); 910 New_Line (Output); 911 end if; 912 913 -- Deallocate all the WT components (both initial and reduced ones) to 914 -- avoid memory leaks. 915 916 for W in 0 .. WT.Last loop 917 918 -- Note: WT.Table (NK) is a temporary variable, do not free it since 919 -- this would cause a double free. 920 921 if W /= NK then 922 Free_Word (WT.Table (W)); 923 end if; 924 end loop; 925 926 WT.Release; 927 IT.Release; 928 929 -- Reset all variables for next usage 930 931 Keys := No_Table; 932 933 Char_Pos_Set := No_Table; 934 Char_Pos_Set_Len := 0; 935 936 Used_Char_Set := No_Table; 937 Used_Char_Set_Len := 0; 938 939 T1 := No_Table; 940 T2 := No_Table; 941 942 T1_Len := 0; 943 T2_Len := 0; 944 945 G := No_Table; 946 G_Len := 0; 947 948 Edges := No_Table; 949 Edges_Len := 0; 950 951 Vertices := No_Table; 952 NV := 0; 953 954 NK := 0; 955 Max_Key_Len := 0; 956 Min_Key_Len := 0; 957 end Finalize; 958 959 ---------------------------- 960 -- Generate_Mapping_Table -- 961 ---------------------------- 962 963 procedure Generate_Mapping_Table 964 (Tab : Integer; 965 L1 : Natural; 966 L2 : Natural; 967 Seed : in out Natural) 968 is 969 begin 970 for J in 0 .. L1 - 1 loop 971 for K in 0 .. L2 - 1 loop 972 Random (Seed); 973 Set_Table (Tab, J, K, Seed mod NV); 974 end loop; 975 end loop; 976 end Generate_Mapping_Table; 977 978 ----------------------------- 979 -- Generate_Mapping_Tables -- 980 ----------------------------- 981 982 procedure Generate_Mapping_Tables 983 (Opt : Optimization; 984 Seed : in out Natural) 985 is 986 begin 987 -- If T1 and T2 are already allocated no need to do it twice. Reuse them 988 -- as their size has not changed. 989 990 if T1 = No_Table and then T2 = No_Table then 991 declare 992 Used_Char_Last : Natural := 0; 993 Used_Char : Natural; 994 995 begin 996 if Opt = CPU_Time then 997 for P in reverse Character'Range loop 998 Used_Char := Get_Used_Char (P); 999 if Used_Char /= 0 then 1000 Used_Char_Last := Used_Char; 1001 exit; 1002 end if; 1003 end loop; 1004 end if; 1005 1006 T1_Len := Char_Pos_Set_Len; 1007 T2_Len := Used_Char_Last + 1; 1008 T1 := Allocate (T1_Len * T2_Len); 1009 T2 := Allocate (T1_Len * T2_Len); 1010 end; 1011 end if; 1012 1013 Generate_Mapping_Table (T1, T1_Len, T2_Len, Seed); 1014 Generate_Mapping_Table (T2, T1_Len, T2_Len, Seed); 1015 1016 if Verbose then 1017 Put_Used_Char_Set (Output, "Used Character Set"); 1018 Put_Int_Matrix (Output, "Function Table 1", T1, 1019 T1_Len, T2_Len); 1020 Put_Int_Matrix (Output, "Function Table 2", T2, 1021 T1_Len, T2_Len); 1022 end if; 1023 end Generate_Mapping_Tables; 1024 1025 ------------------ 1026 -- Get_Char_Pos -- 1027 ------------------ 1028 1029 function Get_Char_Pos (P : Natural) return Natural is 1030 N : constant Natural := Char_Pos_Set + P; 1031 begin 1032 return IT.Table (N); 1033 end Get_Char_Pos; 1034 1035 --------------- 1036 -- Get_Edges -- 1037 --------------- 1038 1039 function Get_Edges (F : Natural) return Edge_Type is 1040 N : constant Natural := Edges + (F * Edge_Size); 1041 E : Edge_Type; 1042 begin 1043 E.X := IT.Table (N); 1044 E.Y := IT.Table (N + 1); 1045 E.Key := IT.Table (N + 2); 1046 return E; 1047 end Get_Edges; 1048 1049 --------------- 1050 -- Get_Graph -- 1051 --------------- 1052 1053 function Get_Graph (N : Natural) return Integer is 1054 begin 1055 return IT.Table (G + N); 1056 end Get_Graph; 1057 1058 ------------- 1059 -- Get_Key -- 1060 ------------- 1061 1062 function Get_Key (N : Key_Id) return Key_Type is 1063 K : Key_Type; 1064 begin 1065 K.Edge := IT.Table (Keys + N); 1066 return K; 1067 end Get_Key; 1068 1069 --------------- 1070 -- Get_Table -- 1071 --------------- 1072 1073 function Get_Table (T : Integer; X, Y : Natural) return Natural is 1074 N : constant Natural := T + (Y * T1_Len) + X; 1075 begin 1076 return IT.Table (N); 1077 end Get_Table; 1078 1079 ------------------- 1080 -- Get_Used_Char -- 1081 ------------------- 1082 1083 function Get_Used_Char (C : Character) return Natural is 1084 N : constant Natural := Used_Char_Set + Character'Pos (C); 1085 begin 1086 return IT.Table (N); 1087 end Get_Used_Char; 1088 1089 ------------------ 1090 -- Get_Vertices -- 1091 ------------------ 1092 1093 function Get_Vertices (F : Natural) return Vertex_Type is 1094 N : constant Natural := Vertices + (F * Vertex_Size); 1095 V : Vertex_Type; 1096 begin 1097 V.First := IT.Table (N); 1098 V.Last := IT.Table (N + 1); 1099 return V; 1100 end Get_Vertices; 1101 1102 ----------- 1103 -- Image -- 1104 ----------- 1105 1106 function Image (Int : Integer; W : Natural := 0) return String is 1107 B : String (1 .. 32); 1108 L : Natural := 0; 1109 1110 procedure Img (V : Natural); 1111 -- Compute image of V into B, starting at B (L), incrementing L 1112 1113 --------- 1114 -- Img -- 1115 --------- 1116 1117 procedure Img (V : Natural) is 1118 begin 1119 if V > 9 then 1120 Img (V / 10); 1121 end if; 1122 1123 L := L + 1; 1124 B (L) := Character'Val ((V mod 10) + Character'Pos ('0')); 1125 end Img; 1126 1127 -- Start of processing for Image 1128 1129 begin 1130 if Int < 0 then 1131 L := L + 1; 1132 B (L) := '-'; 1133 Img (-Int); 1134 else 1135 Img (Int); 1136 end if; 1137 1138 return Image (B (1 .. L), W); 1139 end Image; 1140 1141 ----------- 1142 -- Image -- 1143 ----------- 1144 1145 function Image (Str : String; W : Natural := 0) return String is 1146 Len : constant Natural := Str'Length; 1147 Max : Natural := Len; 1148 1149 begin 1150 if Max < W then 1151 Max := W; 1152 end if; 1153 1154 declare 1155 Buf : String (1 .. Max) := (1 .. Max => ' '); 1156 1157 begin 1158 for J in 0 .. Len - 1 loop 1159 Buf (Max - Len + 1 + J) := Str (Str'First + J); 1160 end loop; 1161 1162 return Buf; 1163 end; 1164 end Image; 1165 1166 ------------- 1167 -- Initial -- 1168 ------------- 1169 1170 function Initial (K : Key_Id) return Word_Id is 1171 begin 1172 return K; 1173 end Initial; 1174 1175 ---------------- 1176 -- Initialize -- 1177 ---------------- 1178 1179 procedure Initialize 1180 (Seed : Natural; 1181 K_To_V : Float := Default_K_To_V; 1182 Optim : Optimization := Memory_Space; 1183 Tries : Positive := Default_Tries) 1184 is 1185 begin 1186 if Verbose then 1187 Put (Output, "Initialize"); 1188 New_Line (Output); 1189 end if; 1190 1191 -- Deallocate the part of the table concerning the reduced words. 1192 -- Initial words are already present in the table. We may have reduced 1193 -- words already there because a previous computation failed. We are 1194 -- currently retrying and the reduced words have to be deallocated. 1195 1196 for W in Reduced (0) .. WT.Last loop 1197 Free_Word (WT.Table (W)); 1198 end loop; 1199 1200 IT.Init; 1201 1202 -- Initialize of computation variables 1203 1204 Keys := No_Table; 1205 1206 Char_Pos_Set := No_Table; 1207 Char_Pos_Set_Len := 0; 1208 1209 Used_Char_Set := No_Table; 1210 Used_Char_Set_Len := 0; 1211 1212 T1 := No_Table; 1213 T2 := No_Table; 1214 1215 T1_Len := 0; 1216 T2_Len := 0; 1217 1218 G := No_Table; 1219 G_Len := 0; 1220 1221 Edges := No_Table; 1222 Edges_Len := 0; 1223 1224 Vertices := No_Table; 1225 NV := 0; 1226 1227 S := Seed; 1228 K2V := K_To_V; 1229 Opt := Optim; 1230 NT := Tries; 1231 1232 if K2V <= 2.0 then 1233 raise Program_Error with "K to V ratio cannot be lower than 2.0"; 1234 end if; 1235 1236 -- Do not accept a value of K2V too close to 2.0 such that once 1237 -- rounded up, NV = 2 * NK because the algorithm would not converge. 1238 1239 NV := Natural (Float (NK) * K2V); 1240 if NV <= 2 * NK then 1241 NV := 2 * NK + 1; 1242 end if; 1243 1244 Keys := Allocate (NK); 1245 1246 -- Resize initial words to have all of them at the same size 1247 -- (so the size of the largest one). 1248 1249 for K in 0 .. NK - 1 loop 1250 Resize_Word (WT.Table (Initial (K)), Max_Key_Len); 1251 end loop; 1252 1253 -- Allocated the table to store the reduced words. As WT is a 1254 -- GNAT.Table (using C memory management), pointers have to be 1255 -- explicitly initialized to null. 1256 1257 WT.Set_Last (Reduced (NK - 1)); 1258 1259 -- Note: Reduced (0) = NK + 1 1260 1261 WT.Table (NK) := null; 1262 1263 for W in 0 .. NK - 1 loop 1264 WT.Table (Reduced (W)) := null; 1265 end loop; 1266 end Initialize; 1267 1268 ------------ 1269 -- Insert -- 1270 ------------ 1271 1272 procedure Insert (Value : String) is 1273 Len : constant Natural := Value'Length; 1274 1275 begin 1276 if Verbose then 1277 Put (Output, "Inserting """ & Value & """"); 1278 New_Line (Output); 1279 end if; 1280 1281 for J in Value'Range loop 1282 pragma Assert (Value (J) /= ASCII.NUL); 1283 null; 1284 end loop; 1285 1286 WT.Set_Last (NK); 1287 WT.Table (NK) := New_Word (Value); 1288 NK := NK + 1; 1289 1290 if Max_Key_Len < Len then 1291 Max_Key_Len := Len; 1292 end if; 1293 1294 if Min_Key_Len = 0 or else Len < Min_Key_Len then 1295 Min_Key_Len := Len; 1296 end if; 1297 end Insert; 1298 1299 -------------- 1300 -- New_Line -- 1301 -------------- 1302 1303 procedure New_Line (File : File_Descriptor) is 1304 begin 1305 if Write (File, EOL'Address, 1) /= 1 then 1306 raise Program_Error; 1307 end if; 1308 end New_Line; 1309 1310 -------------- 1311 -- New_Word -- 1312 -------------- 1313 1314 function New_Word (S : String) return Word_Type is 1315 begin 1316 return new String'(S); 1317 end New_Word; 1318 1319 ------------------------------ 1320 -- Parse_Position_Selection -- 1321 ------------------------------ 1322 1323 procedure Parse_Position_Selection (Argument : String) is 1324 N : Natural := Argument'First; 1325 L : constant Natural := Argument'Last; 1326 M : constant Natural := Max_Key_Len; 1327 1328 T : array (1 .. M) of Boolean := (others => False); 1329 1330 function Parse_Index return Natural; 1331 -- Parse argument starting at index N to find an index 1332 1333 ----------------- 1334 -- Parse_Index -- 1335 ----------------- 1336 1337 function Parse_Index return Natural is 1338 C : Character := Argument (N); 1339 V : Natural := 0; 1340 1341 begin 1342 if C = '$' then 1343 N := N + 1; 1344 return M; 1345 end if; 1346 1347 if C not in '0' .. '9' then 1348 raise Program_Error with "cannot read position argument"; 1349 end if; 1350 1351 while C in '0' .. '9' loop 1352 V := V * 10 + (Character'Pos (C) - Character'Pos ('0')); 1353 N := N + 1; 1354 exit when L < N; 1355 C := Argument (N); 1356 end loop; 1357 1358 return V; 1359 end Parse_Index; 1360 1361 -- Start of processing for Parse_Position_Selection 1362 1363 begin 1364 -- Empty specification means all the positions 1365 1366 if L < N then 1367 Char_Pos_Set_Len := M; 1368 Char_Pos_Set := Allocate (Char_Pos_Set_Len); 1369 1370 for C in 0 .. Char_Pos_Set_Len - 1 loop 1371 Set_Char_Pos (C, C + 1); 1372 end loop; 1373 1374 else 1375 loop 1376 declare 1377 First, Last : Natural; 1378 1379 begin 1380 First := Parse_Index; 1381 Last := First; 1382 1383 -- Detect a range 1384 1385 if N <= L and then Argument (N) = '-' then 1386 N := N + 1; 1387 Last := Parse_Index; 1388 end if; 1389 1390 -- Include the positions in the selection 1391 1392 for J in First .. Last loop 1393 T (J) := True; 1394 end loop; 1395 end; 1396 1397 exit when L < N; 1398 1399 if Argument (N) /= ',' then 1400 raise Program_Error with "cannot read position argument"; 1401 end if; 1402 1403 N := N + 1; 1404 end loop; 1405 1406 -- Compute position selection length 1407 1408 N := 0; 1409 for J in T'Range loop 1410 if T (J) then 1411 N := N + 1; 1412 end if; 1413 end loop; 1414 1415 -- Fill position selection 1416 1417 Char_Pos_Set_Len := N; 1418 Char_Pos_Set := Allocate (Char_Pos_Set_Len); 1419 1420 N := 0; 1421 for J in T'Range loop 1422 if T (J) then 1423 Set_Char_Pos (N, J); 1424 N := N + 1; 1425 end if; 1426 end loop; 1427 end if; 1428 end Parse_Position_Selection; 1429 1430 ------------- 1431 -- Produce -- 1432 ------------- 1433 1434 procedure Produce 1435 (Pkg_Name : String := Default_Pkg_Name; 1436 Use_Stdout : Boolean := False) 1437 is 1438 File : File_Descriptor := Standout; 1439 1440 Status : Boolean; 1441 -- For call to Close 1442 1443 function Array_Img (N, T, R1 : String; R2 : String := "") return String; 1444 -- Return string "N : constant array (R1[, R2]) of T;" 1445 1446 function Range_Img (F, L : Natural; T : String := "") return String; 1447 -- Return string "[T range ]F .. L" 1448 1449 function Type_Img (L : Natural) return String; 1450 -- Return the larger unsigned type T such that T'Last < L 1451 1452 --------------- 1453 -- Array_Img -- 1454 --------------- 1455 1456 function Array_Img 1457 (N, T, R1 : String; 1458 R2 : String := "") return String 1459 is 1460 begin 1461 Last := 0; 1462 Add (" "); 1463 Add (N); 1464 Add (" : constant array ("); 1465 Add (R1); 1466 1467 if R2 /= "" then 1468 Add (", "); 1469 Add (R2); 1470 end if; 1471 1472 Add (") of "); 1473 Add (T); 1474 Add (" :="); 1475 return Line (1 .. Last); 1476 end Array_Img; 1477 1478 --------------- 1479 -- Range_Img -- 1480 --------------- 1481 1482 function Range_Img (F, L : Natural; T : String := "") return String is 1483 FI : constant String := Image (F); 1484 FL : constant Natural := FI'Length; 1485 LI : constant String := Image (L); 1486 LL : constant Natural := LI'Length; 1487 TL : constant Natural := T'Length; 1488 RI : String (1 .. TL + 7 + FL + 4 + LL); 1489 Len : Natural := 0; 1490 1491 begin 1492 if TL /= 0 then 1493 RI (Len + 1 .. Len + TL) := T; 1494 Len := Len + TL; 1495 RI (Len + 1 .. Len + 7) := " range "; 1496 Len := Len + 7; 1497 end if; 1498 1499 RI (Len + 1 .. Len + FL) := FI; 1500 Len := Len + FL; 1501 RI (Len + 1 .. Len + 4) := " .. "; 1502 Len := Len + 4; 1503 RI (Len + 1 .. Len + LL) := LI; 1504 Len := Len + LL; 1505 return RI (1 .. Len); 1506 end Range_Img; 1507 1508 -------------- 1509 -- Type_Img -- 1510 -------------- 1511 1512 function Type_Img (L : Natural) return String is 1513 S : constant String := Image (Type_Size (L)); 1514 U : String := "Unsigned_ "; 1515 N : Natural := 9; 1516 1517 begin 1518 for J in S'Range loop 1519 N := N + 1; 1520 U (N) := S (J); 1521 end loop; 1522 1523 return U (1 .. N); 1524 end Type_Img; 1525 1526 F : Natural; 1527 L : Natural; 1528 P : Natural; 1529 1530 FName : String := Ada_File_Base_Name (Pkg_Name) & ".ads"; 1531 -- Initially, the name of the spec file, then modified to be the name of 1532 -- the body file. Not used if Use_Stdout is True. 1533 1534 -- Start of processing for Produce 1535 1536 begin 1537 1538 if Verbose and then not Use_Stdout then 1539 Put (Output, 1540 "Producing " & Ada.Directories.Current_Directory & "/" & FName); 1541 New_Line (Output); 1542 end if; 1543 1544 if not Use_Stdout then 1545 File := Create_File (FName, Binary); 1546 1547 if File = Invalid_FD then 1548 raise Program_Error with "cannot create: " & FName; 1549 end if; 1550 end if; 1551 1552 Put (File, "package "); 1553 Put (File, Pkg_Name); 1554 Put (File, " is"); 1555 New_Line (File); 1556 Put (File, " function Hash (S : String) return Natural;"); 1557 New_Line (File); 1558 Put (File, "end "); 1559 Put (File, Pkg_Name); 1560 Put (File, ";"); 1561 New_Line (File); 1562 1563 if not Use_Stdout then 1564 Close (File, Status); 1565 1566 if not Status then 1567 raise Device_Error; 1568 end if; 1569 end if; 1570 1571 if not Use_Stdout then 1572 1573 -- Set to body file name 1574 1575 FName (FName'Last) := 'b'; 1576 1577 File := Create_File (FName, Binary); 1578 1579 if File = Invalid_FD then 1580 raise Program_Error with "cannot create: " & FName; 1581 end if; 1582 end if; 1583 1584 Put (File, "with Interfaces; use Interfaces;"); 1585 New_Line (File); 1586 New_Line (File); 1587 Put (File, "package body "); 1588 Put (File, Pkg_Name); 1589 Put (File, " is"); 1590 New_Line (File); 1591 New_Line (File); 1592 1593 if Opt = CPU_Time then 1594 Put (File, Array_Img ("C", Type_Img (256), "Character")); 1595 New_Line (File); 1596 1597 F := Character'Pos (Character'First); 1598 L := Character'Pos (Character'Last); 1599 1600 for J in Character'Range loop 1601 P := Get_Used_Char (J); 1602 Put (File, Image (P), 1, 0, 1, F, L, Character'Pos (J)); 1603 end loop; 1604 1605 New_Line (File); 1606 end if; 1607 1608 F := 0; 1609 L := Char_Pos_Set_Len - 1; 1610 1611 Put (File, Array_Img ("P", "Natural", Range_Img (F, L))); 1612 New_Line (File); 1613 1614 for J in F .. L loop 1615 Put (File, Image (Get_Char_Pos (J)), 1, 0, 1, F, L, J); 1616 end loop; 1617 1618 New_Line (File); 1619 1620 case Opt is 1621 when CPU_Time => 1622 Put_Int_Matrix 1623 (File, 1624 Array_Img ("T1", Type_Img (NV), 1625 Range_Img (0, T1_Len - 1), 1626 Range_Img (0, T2_Len - 1, Type_Img (256))), 1627 T1, T1_Len, T2_Len); 1628 1629 when Memory_Space => 1630 Put_Int_Matrix 1631 (File, 1632 Array_Img ("T1", Type_Img (NV), 1633 Range_Img (0, T1_Len - 1)), 1634 T1, T1_Len, 0); 1635 end case; 1636 1637 New_Line (File); 1638 1639 case Opt is 1640 when CPU_Time => 1641 Put_Int_Matrix 1642 (File, 1643 Array_Img ("T2", Type_Img (NV), 1644 Range_Img (0, T1_Len - 1), 1645 Range_Img (0, T2_Len - 1, Type_Img (256))), 1646 T2, T1_Len, T2_Len); 1647 1648 when Memory_Space => 1649 Put_Int_Matrix 1650 (File, 1651 Array_Img ("T2", Type_Img (NV), 1652 Range_Img (0, T1_Len - 1)), 1653 T2, T1_Len, 0); 1654 end case; 1655 1656 New_Line (File); 1657 1658 Put_Int_Vector 1659 (File, 1660 Array_Img ("G", Type_Img (NK), 1661 Range_Img (0, G_Len - 1)), 1662 G, G_Len); 1663 New_Line (File); 1664 1665 Put (File, " function Hash (S : String) return Natural is"); 1666 New_Line (File); 1667 Put (File, " F : constant Natural := S'First - 1;"); 1668 New_Line (File); 1669 Put (File, " L : constant Natural := S'Length;"); 1670 New_Line (File); 1671 Put (File, " F1, F2 : Natural := 0;"); 1672 New_Line (File); 1673 1674 Put (File, " J : "); 1675 1676 case Opt is 1677 when CPU_Time => 1678 Put (File, Type_Img (256)); 1679 1680 when Memory_Space => 1681 Put (File, "Natural"); 1682 end case; 1683 1684 Put (File, ";"); 1685 New_Line (File); 1686 1687 Put (File, " begin"); 1688 New_Line (File); 1689 Put (File, " for K in P'Range loop"); 1690 New_Line (File); 1691 Put (File, " exit when L < P (K);"); 1692 New_Line (File); 1693 Put (File, " J := "); 1694 1695 case Opt is 1696 when CPU_Time => 1697 Put (File, "C"); 1698 1699 when Memory_Space => 1700 Put (File, "Character'Pos"); 1701 end case; 1702 1703 Put (File, " (S (P (K) + F));"); 1704 New_Line (File); 1705 1706 Put (File, " F1 := (F1 + Natural (T1 (K"); 1707 1708 if Opt = CPU_Time then 1709 Put (File, ", J"); 1710 end if; 1711 1712 Put (File, "))"); 1713 1714 if Opt = Memory_Space then 1715 Put (File, " * J"); 1716 end if; 1717 1718 Put (File, ") mod "); 1719 Put (File, Image (NV)); 1720 Put (File, ";"); 1721 New_Line (File); 1722 1723 Put (File, " F2 := (F2 + Natural (T2 (K"); 1724 1725 if Opt = CPU_Time then 1726 Put (File, ", J"); 1727 end if; 1728 1729 Put (File, "))"); 1730 1731 if Opt = Memory_Space then 1732 Put (File, " * J"); 1733 end if; 1734 1735 Put (File, ") mod "); 1736 Put (File, Image (NV)); 1737 Put (File, ";"); 1738 New_Line (File); 1739 1740 Put (File, " end loop;"); 1741 New_Line (File); 1742 1743 Put (File, 1744 " return (Natural (G (F1)) + Natural (G (F2))) mod "); 1745 1746 Put (File, Image (NK)); 1747 Put (File, ";"); 1748 New_Line (File); 1749 Put (File, " end Hash;"); 1750 New_Line (File); 1751 New_Line (File); 1752 Put (File, "end "); 1753 Put (File, Pkg_Name); 1754 Put (File, ";"); 1755 New_Line (File); 1756 1757 if not Use_Stdout then 1758 Close (File, Status); 1759 1760 if not Status then 1761 raise Device_Error; 1762 end if; 1763 end if; 1764 end Produce; 1765 1766 --------- 1767 -- Put -- 1768 --------- 1769 1770 procedure Put (File : File_Descriptor; Str : String) is 1771 Len : constant Natural := Str'Length; 1772 begin 1773 for J in Str'Range loop 1774 pragma Assert (Str (J) /= ASCII.NUL); 1775 null; 1776 end loop; 1777 1778 if Write (File, Str'Address, Len) /= Len then 1779 raise Program_Error; 1780 end if; 1781 end Put; 1782 1783 --------- 1784 -- Put -- 1785 --------- 1786 1787 procedure Put 1788 (F : File_Descriptor; 1789 S : String; 1790 F1 : Natural; 1791 L1 : Natural; 1792 C1 : Natural; 1793 F2 : Natural; 1794 L2 : Natural; 1795 C2 : Natural) 1796 is 1797 Len : constant Natural := S'Length; 1798 1799 procedure Flush; 1800 -- Write current line, followed by LF 1801 1802 ----------- 1803 -- Flush -- 1804 ----------- 1805 1806 procedure Flush is 1807 begin 1808 Put (F, Line (1 .. Last)); 1809 New_Line (F); 1810 Last := 0; 1811 end Flush; 1812 1813 -- Start of processing for Put 1814 1815 begin 1816 if C1 = F1 and then C2 = F2 then 1817 Last := 0; 1818 end if; 1819 1820 if Last + Len + 3 >= Max then 1821 Flush; 1822 end if; 1823 1824 if Last = 0 then 1825 Add (" "); 1826 1827 if F1 <= L1 then 1828 if C1 = F1 and then C2 = F2 then 1829 Add ('('); 1830 1831 if F1 = L1 then 1832 Add ("0 .. 0 => "); 1833 end if; 1834 1835 else 1836 Add (' '); 1837 end if; 1838 end if; 1839 end if; 1840 1841 if C2 = F2 then 1842 Add ('('); 1843 1844 if F2 = L2 then 1845 Add ("0 .. 0 => "); 1846 end if; 1847 1848 else 1849 Add (' '); 1850 end if; 1851 1852 Add (S); 1853 1854 if C2 = L2 then 1855 Add (')'); 1856 1857 if F1 > L1 then 1858 Add (';'); 1859 Flush; 1860 1861 elsif C1 /= L1 then 1862 Add (','); 1863 Flush; 1864 1865 else 1866 Add (')'); 1867 Add (';'); 1868 Flush; 1869 end if; 1870 1871 else 1872 Add (','); 1873 end if; 1874 end Put; 1875 1876 --------------- 1877 -- Put_Edges -- 1878 --------------- 1879 1880 procedure Put_Edges (File : File_Descriptor; Title : String) is 1881 E : Edge_Type; 1882 F1 : constant Natural := 1; 1883 L1 : constant Natural := Edges_Len - 1; 1884 M : constant Natural := Max / 5; 1885 1886 begin 1887 Put (File, Title); 1888 New_Line (File); 1889 1890 -- Edges valid range is 1 .. Edge_Len - 1 1891 1892 for J in F1 .. L1 loop 1893 E := Get_Edges (J); 1894 Put (File, Image (J, M), F1, L1, J, 1, 4, 1); 1895 Put (File, Image (E.X, M), F1, L1, J, 1, 4, 2); 1896 Put (File, Image (E.Y, M), F1, L1, J, 1, 4, 3); 1897 Put (File, Image (E.Key, M), F1, L1, J, 1, 4, 4); 1898 end loop; 1899 end Put_Edges; 1900 1901 ---------------------- 1902 -- Put_Initial_Keys -- 1903 ---------------------- 1904 1905 procedure Put_Initial_Keys (File : File_Descriptor; Title : String) is 1906 F1 : constant Natural := 0; 1907 L1 : constant Natural := NK - 1; 1908 M : constant Natural := Max / 5; 1909 K : Key_Type; 1910 1911 begin 1912 Put (File, Title); 1913 New_Line (File); 1914 1915 for J in F1 .. L1 loop 1916 K := Get_Key (J); 1917 Put (File, Image (J, M), F1, L1, J, 1, 3, 1); 1918 Put (File, Image (K.Edge, M), F1, L1, J, 1, 3, 2); 1919 Put (File, Trim_Trailing_Nuls (WT.Table (Initial (J)).all), 1920 F1, L1, J, 1, 3, 3); 1921 end loop; 1922 end Put_Initial_Keys; 1923 1924 -------------------- 1925 -- Put_Int_Matrix -- 1926 -------------------- 1927 1928 procedure Put_Int_Matrix 1929 (File : File_Descriptor; 1930 Title : String; 1931 Table : Integer; 1932 Len_1 : Natural; 1933 Len_2 : Natural) 1934 is 1935 F1 : constant Integer := 0; 1936 L1 : constant Integer := Len_1 - 1; 1937 F2 : constant Integer := 0; 1938 L2 : constant Integer := Len_2 - 1; 1939 Ix : Natural; 1940 1941 begin 1942 Put (File, Title); 1943 New_Line (File); 1944 1945 if Len_2 = 0 then 1946 for J in F1 .. L1 loop 1947 Ix := IT.Table (Table + J); 1948 Put (File, Image (Ix), 1, 0, 1, F1, L1, J); 1949 end loop; 1950 1951 else 1952 for J in F1 .. L1 loop 1953 for K in F2 .. L2 loop 1954 Ix := IT.Table (Table + J + K * Len_1); 1955 Put (File, Image (Ix), F1, L1, J, F2, L2, K); 1956 end loop; 1957 end loop; 1958 end if; 1959 end Put_Int_Matrix; 1960 1961 -------------------- 1962 -- Put_Int_Vector -- 1963 -------------------- 1964 1965 procedure Put_Int_Vector 1966 (File : File_Descriptor; 1967 Title : String; 1968 Vector : Integer; 1969 Length : Natural) 1970 is 1971 F2 : constant Natural := 0; 1972 L2 : constant Natural := Length - 1; 1973 1974 begin 1975 Put (File, Title); 1976 New_Line (File); 1977 1978 for J in F2 .. L2 loop 1979 Put (File, Image (IT.Table (Vector + J)), 1, 0, 1, F2, L2, J); 1980 end loop; 1981 end Put_Int_Vector; 1982 1983 ---------------------- 1984 -- Put_Reduced_Keys -- 1985 ---------------------- 1986 1987 procedure Put_Reduced_Keys (File : File_Descriptor; Title : String) is 1988 F1 : constant Natural := 0; 1989 L1 : constant Natural := NK - 1; 1990 M : constant Natural := Max / 5; 1991 K : Key_Type; 1992 1993 begin 1994 Put (File, Title); 1995 New_Line (File); 1996 1997 for J in F1 .. L1 loop 1998 K := Get_Key (J); 1999 Put (File, Image (J, M), F1, L1, J, 1, 3, 1); 2000 Put (File, Image (K.Edge, M), F1, L1, J, 1, 3, 2); 2001 Put (File, Trim_Trailing_Nuls (WT.Table (Reduced (J)).all), 2002 F1, L1, J, 1, 3, 3); 2003 end loop; 2004 end Put_Reduced_Keys; 2005 2006 ----------------------- 2007 -- Put_Used_Char_Set -- 2008 ----------------------- 2009 2010 procedure Put_Used_Char_Set (File : File_Descriptor; Title : String) is 2011 F : constant Natural := Character'Pos (Character'First); 2012 L : constant Natural := Character'Pos (Character'Last); 2013 2014 begin 2015 Put (File, Title); 2016 New_Line (File); 2017 2018 for J in Character'Range loop 2019 Put 2020 (File, Image (Get_Used_Char (J)), 1, 0, 1, F, L, Character'Pos (J)); 2021 end loop; 2022 end Put_Used_Char_Set; 2023 2024 ---------------------- 2025 -- Put_Vertex_Table -- 2026 ---------------------- 2027 2028 procedure Put_Vertex_Table (File : File_Descriptor; Title : String) is 2029 F1 : constant Natural := 0; 2030 L1 : constant Natural := NV - 1; 2031 M : constant Natural := Max / 4; 2032 V : Vertex_Type; 2033 2034 begin 2035 Put (File, Title); 2036 New_Line (File); 2037 2038 for J in F1 .. L1 loop 2039 V := Get_Vertices (J); 2040 Put (File, Image (J, M), F1, L1, J, 1, 3, 1); 2041 Put (File, Image (V.First, M), F1, L1, J, 1, 3, 2); 2042 Put (File, Image (V.Last, M), F1, L1, J, 1, 3, 3); 2043 end loop; 2044 end Put_Vertex_Table; 2045 2046 ------------ 2047 -- Random -- 2048 ------------ 2049 2050 procedure Random (Seed : in out Natural) is 2051 2052 -- Park & Miller Standard Minimal using Schrage's algorithm to avoid 2053 -- overflow: Xn+1 = 16807 * Xn mod (2 ** 31 - 1) 2054 2055 R : Natural; 2056 Q : Natural; 2057 X : Integer; 2058 2059 begin 2060 R := Seed mod 127773; 2061 Q := Seed / 127773; 2062 X := 16807 * R - 2836 * Q; 2063 2064 Seed := (if X < 0 then X + 2147483647 else X); 2065 end Random; 2066 2067 ------------- 2068 -- Reduced -- 2069 ------------- 2070 2071 function Reduced (K : Key_Id) return Word_Id is 2072 begin 2073 return K + NK + 1; 2074 end Reduced; 2075 2076 ----------------- 2077 -- Resize_Word -- 2078 ----------------- 2079 2080 procedure Resize_Word (W : in out Word_Type; Len : Natural) is 2081 S1 : constant String := W.all; 2082 S2 : String (1 .. Len) := (others => ASCII.NUL); 2083 L : constant Natural := S1'Length; 2084 begin 2085 if L /= Len then 2086 Free_Word (W); 2087 S2 (1 .. L) := S1; 2088 W := New_Word (S2); 2089 end if; 2090 end Resize_Word; 2091 2092 -------------------------- 2093 -- Select_Char_Position -- 2094 -------------------------- 2095 2096 procedure Select_Char_Position is 2097 2098 type Vertex_Table_Type is array (Natural range <>) of Vertex_Type; 2099 2100 procedure Build_Identical_Keys_Sets 2101 (Table : in out Vertex_Table_Type; 2102 Last : in out Natural; 2103 Pos : Natural); 2104 -- Build a list of keys subsets that are identical with the current 2105 -- position selection plus Pos. Once this routine is called, reduced 2106 -- words are sorted by subsets and each item (First, Last) in Sets 2107 -- defines the range of identical keys. 2108 -- Need comment saying exactly what Last is ??? 2109 2110 function Count_Different_Keys 2111 (Table : Vertex_Table_Type; 2112 Last : Natural; 2113 Pos : Natural) return Natural; 2114 -- For each subset in Sets, count the number of different keys if we add 2115 -- Pos to the current position selection. 2116 2117 Sel_Position : IT.Table_Type (1 .. Max_Key_Len); 2118 Last_Sel_Pos : Natural := 0; 2119 Max_Sel_Pos : Natural := 0; 2120 2121 ------------------------------- 2122 -- Build_Identical_Keys_Sets -- 2123 ------------------------------- 2124 2125 procedure Build_Identical_Keys_Sets 2126 (Table : in out Vertex_Table_Type; 2127 Last : in out Natural; 2128 Pos : Natural) 2129 is 2130 S : constant Vertex_Table_Type := Table (Table'First .. Last); 2131 C : constant Natural := Pos; 2132 -- Shortcuts (why are these not renames ???) 2133 2134 F : Integer; 2135 L : Integer; 2136 -- First and last words of a subset 2137 2138 Offset : Natural; 2139 -- GNAT.Heap_Sort assumes that the first array index is 1. Offset 2140 -- defines the translation to operate. 2141 2142 function Lt (L, R : Natural) return Boolean; 2143 procedure Move (From : Natural; To : Natural); 2144 -- Subprograms needed by GNAT.Heap_Sort_G 2145 2146 -------- 2147 -- Lt -- 2148 -------- 2149 2150 function Lt (L, R : Natural) return Boolean is 2151 C : constant Natural := Pos; 2152 Left : Natural; 2153 Right : Natural; 2154 2155 begin 2156 if L = 0 then 2157 Left := NK; 2158 Right := Offset + R; 2159 elsif R = 0 then 2160 Left := Offset + L; 2161 Right := NK; 2162 else 2163 Left := Offset + L; 2164 Right := Offset + R; 2165 end if; 2166 2167 return WT.Table (Left)(C) < WT.Table (Right)(C); 2168 end Lt; 2169 2170 ---------- 2171 -- Move -- 2172 ---------- 2173 2174 procedure Move (From : Natural; To : Natural) is 2175 Target, Source : Natural; 2176 2177 begin 2178 if From = 0 then 2179 Source := NK; 2180 Target := Offset + To; 2181 elsif To = 0 then 2182 Source := Offset + From; 2183 Target := NK; 2184 else 2185 Source := Offset + From; 2186 Target := Offset + To; 2187 end if; 2188 2189 WT.Table (Target) := WT.Table (Source); 2190 WT.Table (Source) := null; 2191 end Move; 2192 2193 package Sorting is new GNAT.Heap_Sort_G (Move, Lt); 2194 2195 -- Start of processing for Build_Identical_Key_Sets 2196 2197 begin 2198 Last := 0; 2199 2200 -- For each subset in S, extract the new subsets we have by adding C 2201 -- in the position selection. 2202 2203 for J in S'Range loop 2204 if S (J).First = S (J).Last then 2205 F := S (J).First; 2206 L := S (J).Last; 2207 Last := Last + 1; 2208 Table (Last) := (F, L); 2209 2210 else 2211 Offset := Reduced (S (J).First) - 1; 2212 Sorting.Sort (S (J).Last - S (J).First + 1); 2213 2214 F := S (J).First; 2215 L := F; 2216 for N in S (J).First .. S (J).Last loop 2217 2218 -- For the last item, close the last subset 2219 2220 if N = S (J).Last then 2221 Last := Last + 1; 2222 Table (Last) := (F, N); 2223 2224 -- Two contiguous words are identical when they have the 2225 -- same Cth character. 2226 2227 elsif WT.Table (Reduced (N))(C) = 2228 WT.Table (Reduced (N + 1))(C) 2229 then 2230 L := N + 1; 2231 2232 -- Find a new subset of identical keys. Store the current 2233 -- one and create a new subset. 2234 2235 else 2236 Last := Last + 1; 2237 Table (Last) := (F, L); 2238 F := N + 1; 2239 L := F; 2240 end if; 2241 end loop; 2242 end if; 2243 end loop; 2244 end Build_Identical_Keys_Sets; 2245 2246 -------------------------- 2247 -- Count_Different_Keys -- 2248 -------------------------- 2249 2250 function Count_Different_Keys 2251 (Table : Vertex_Table_Type; 2252 Last : Natural; 2253 Pos : Natural) return Natural 2254 is 2255 N : array (Character) of Natural; 2256 C : Character; 2257 T : Natural := 0; 2258 2259 begin 2260 -- For each subset, count the number of words that are still 2261 -- different when we include Pos in the position selection. Only 2262 -- focus on this position as the other positions already produce 2263 -- identical keys. 2264 2265 for S in 1 .. Last loop 2266 2267 -- Count the occurrences of the different characters 2268 2269 N := (others => 0); 2270 for K in Table (S).First .. Table (S).Last loop 2271 C := WT.Table (Reduced (K))(Pos); 2272 N (C) := N (C) + 1; 2273 end loop; 2274 2275 -- Update the number of different keys. Each character used 2276 -- denotes a different key. 2277 2278 for J in N'Range loop 2279 if N (J) > 0 then 2280 T := T + 1; 2281 end if; 2282 end loop; 2283 end loop; 2284 2285 return T; 2286 end Count_Different_Keys; 2287 2288 -- Start of processing for Select_Char_Position 2289 2290 begin 2291 -- Initialize the reduced words set 2292 2293 for K in 0 .. NK - 1 loop 2294 WT.Table (Reduced (K)) := New_Word (WT.Table (Initial (K)).all); 2295 end loop; 2296 2297 declare 2298 Differences : Natural; 2299 Max_Differences : Natural := 0; 2300 Old_Differences : Natural; 2301 Max_Diff_Sel_Pos : Natural := 0; -- init to kill warning 2302 Max_Diff_Sel_Pos_Idx : Natural := 0; -- init to kill warning 2303 Same_Keys_Sets_Table : Vertex_Table_Type (1 .. NK); 2304 Same_Keys_Sets_Last : Natural := 1; 2305 2306 begin 2307 for C in Sel_Position'Range loop 2308 Sel_Position (C) := C; 2309 end loop; 2310 2311 Same_Keys_Sets_Table (1) := (0, NK - 1); 2312 2313 loop 2314 -- Preserve maximum number of different keys and check later on 2315 -- that this value is strictly incrementing. Otherwise, it means 2316 -- that two keys are strictly identical. 2317 2318 Old_Differences := Max_Differences; 2319 2320 -- The first position should not exceed the minimum key length. 2321 -- Otherwise, we may end up with an empty word once reduced. 2322 2323 Max_Sel_Pos := 2324 (if Last_Sel_Pos = 0 then Min_Key_Len else Max_Key_Len); 2325 2326 -- Find which position increases more the number of differences 2327 2328 for J in Last_Sel_Pos + 1 .. Max_Sel_Pos loop 2329 Differences := Count_Different_Keys 2330 (Same_Keys_Sets_Table, 2331 Same_Keys_Sets_Last, 2332 Sel_Position (J)); 2333 2334 if Verbose then 2335 Put (Output, 2336 "Selecting position" & Sel_Position (J)'Img & 2337 " results in" & Differences'Img & 2338 " differences"); 2339 New_Line (Output); 2340 end if; 2341 2342 if Differences > Max_Differences then 2343 Max_Differences := Differences; 2344 Max_Diff_Sel_Pos := Sel_Position (J); 2345 Max_Diff_Sel_Pos_Idx := J; 2346 end if; 2347 end loop; 2348 2349 if Old_Differences = Max_Differences then 2350 raise Program_Error with "some keys are identical"; 2351 end if; 2352 2353 -- Insert selected position and sort Sel_Position table 2354 2355 Last_Sel_Pos := Last_Sel_Pos + 1; 2356 Sel_Position (Last_Sel_Pos + 1 .. Max_Diff_Sel_Pos_Idx) := 2357 Sel_Position (Last_Sel_Pos .. Max_Diff_Sel_Pos_Idx - 1); 2358 Sel_Position (Last_Sel_Pos) := Max_Diff_Sel_Pos; 2359 2360 for P in 1 .. Last_Sel_Pos - 1 loop 2361 if Max_Diff_Sel_Pos < Sel_Position (P) then 2362 Sel_Position (P + 1 .. Last_Sel_Pos) := 2363 Sel_Position (P .. Last_Sel_Pos - 1); 2364 Sel_Position (P) := Max_Diff_Sel_Pos; 2365 exit; 2366 end if; 2367 end loop; 2368 2369 exit when Max_Differences = NK; 2370 2371 Build_Identical_Keys_Sets 2372 (Same_Keys_Sets_Table, 2373 Same_Keys_Sets_Last, 2374 Max_Diff_Sel_Pos); 2375 2376 if Verbose then 2377 Put (Output, 2378 "Selecting position" & Max_Diff_Sel_Pos'Img & 2379 " results in" & Max_Differences'Img & 2380 " differences"); 2381 New_Line (Output); 2382 Put (Output, "--"); 2383 New_Line (Output); 2384 for J in 1 .. Same_Keys_Sets_Last loop 2385 for K in 2386 Same_Keys_Sets_Table (J).First .. 2387 Same_Keys_Sets_Table (J).Last 2388 loop 2389 Put (Output, 2390 Trim_Trailing_Nuls (WT.Table (Reduced (K)).all)); 2391 New_Line (Output); 2392 end loop; 2393 Put (Output, "--"); 2394 New_Line (Output); 2395 end loop; 2396 end if; 2397 end loop; 2398 end; 2399 2400 Char_Pos_Set_Len := Last_Sel_Pos; 2401 Char_Pos_Set := Allocate (Char_Pos_Set_Len); 2402 2403 for C in 1 .. Last_Sel_Pos loop 2404 Set_Char_Pos (C - 1, Sel_Position (C)); 2405 end loop; 2406 end Select_Char_Position; 2407 2408 -------------------------- 2409 -- Select_Character_Set -- 2410 -------------------------- 2411 2412 procedure Select_Character_Set is 2413 Last : Natural := 0; 2414 Used : array (Character) of Boolean := (others => False); 2415 Char : Character; 2416 2417 begin 2418 for J in 0 .. NK - 1 loop 2419 for K in 0 .. Char_Pos_Set_Len - 1 loop 2420 Char := WT.Table (Initial (J))(Get_Char_Pos (K)); 2421 exit when Char = ASCII.NUL; 2422 Used (Char) := True; 2423 end loop; 2424 end loop; 2425 2426 Used_Char_Set_Len := 256; 2427 Used_Char_Set := Allocate (Used_Char_Set_Len); 2428 2429 for J in Used'Range loop 2430 if Used (J) then 2431 Set_Used_Char (J, Last); 2432 Last := Last + 1; 2433 else 2434 Set_Used_Char (J, 0); 2435 end if; 2436 end loop; 2437 end Select_Character_Set; 2438 2439 ------------------ 2440 -- Set_Char_Pos -- 2441 ------------------ 2442 2443 procedure Set_Char_Pos (P : Natural; Item : Natural) is 2444 N : constant Natural := Char_Pos_Set + P; 2445 begin 2446 IT.Table (N) := Item; 2447 end Set_Char_Pos; 2448 2449 --------------- 2450 -- Set_Edges -- 2451 --------------- 2452 2453 procedure Set_Edges (F : Natural; Item : Edge_Type) is 2454 N : constant Natural := Edges + (F * Edge_Size); 2455 begin 2456 IT.Table (N) := Item.X; 2457 IT.Table (N + 1) := Item.Y; 2458 IT.Table (N + 2) := Item.Key; 2459 end Set_Edges; 2460 2461 --------------- 2462 -- Set_Graph -- 2463 --------------- 2464 2465 procedure Set_Graph (N : Natural; Item : Integer) is 2466 begin 2467 IT.Table (G + N) := Item; 2468 end Set_Graph; 2469 2470 ------------- 2471 -- Set_Key -- 2472 ------------- 2473 2474 procedure Set_Key (N : Key_Id; Item : Key_Type) is 2475 begin 2476 IT.Table (Keys + N) := Item.Edge; 2477 end Set_Key; 2478 2479 --------------- 2480 -- Set_Table -- 2481 --------------- 2482 2483 procedure Set_Table (T : Integer; X, Y : Natural; Item : Natural) is 2484 N : constant Natural := T + ((Y * T1_Len) + X); 2485 begin 2486 IT.Table (N) := Item; 2487 end Set_Table; 2488 2489 ------------------- 2490 -- Set_Used_Char -- 2491 ------------------- 2492 2493 procedure Set_Used_Char (C : Character; Item : Natural) is 2494 N : constant Natural := Used_Char_Set + Character'Pos (C); 2495 begin 2496 IT.Table (N) := Item; 2497 end Set_Used_Char; 2498 2499 ------------------ 2500 -- Set_Vertices -- 2501 ------------------ 2502 2503 procedure Set_Vertices (F : Natural; Item : Vertex_Type) is 2504 N : constant Natural := Vertices + (F * Vertex_Size); 2505 begin 2506 IT.Table (N) := Item.First; 2507 IT.Table (N + 1) := Item.Last; 2508 end Set_Vertices; 2509 2510 --------- 2511 -- Sum -- 2512 --------- 2513 2514 function Sum 2515 (Word : Word_Type; 2516 Table : Table_Id; 2517 Opt : Optimization) return Natural 2518 is 2519 S : Natural := 0; 2520 R : Natural; 2521 2522 begin 2523 case Opt is 2524 when CPU_Time => 2525 for J in 0 .. T1_Len - 1 loop 2526 exit when Word (J + 1) = ASCII.NUL; 2527 R := Get_Table (Table, J, Get_Used_Char (Word (J + 1))); 2528 S := (S + R) mod NV; 2529 end loop; 2530 2531 when Memory_Space => 2532 for J in 0 .. T1_Len - 1 loop 2533 exit when Word (J + 1) = ASCII.NUL; 2534 R := Get_Table (Table, J, 0); 2535 S := (S + R * Character'Pos (Word (J + 1))) mod NV; 2536 end loop; 2537 end case; 2538 2539 return S; 2540 end Sum; 2541 2542 ------------------------ 2543 -- Trim_Trailing_Nuls -- 2544 ------------------------ 2545 2546 function Trim_Trailing_Nuls (Str : String) return String is 2547 begin 2548 for J in reverse Str'Range loop 2549 if Str (J) /= ASCII.NUL then 2550 return Str (Str'First .. J); 2551 end if; 2552 end loop; 2553 2554 return Str; 2555 end Trim_Trailing_Nuls; 2556 2557 --------------- 2558 -- Type_Size -- 2559 --------------- 2560 2561 function Type_Size (L : Natural) return Natural is 2562 begin 2563 if L <= 2 ** 8 then 2564 return 8; 2565 elsif L <= 2 ** 16 then 2566 return 16; 2567 else 2568 return 32; 2569 end if; 2570 end Type_Size; 2571 2572 ----------- 2573 -- Value -- 2574 ----------- 2575 2576 function Value 2577 (Name : Table_Name; 2578 J : Natural; 2579 K : Natural := 0) return Natural 2580 is 2581 begin 2582 case Name is 2583 when Character_Position => 2584 return Get_Char_Pos (J); 2585 2586 when Used_Character_Set => 2587 return Get_Used_Char (Character'Val (J)); 2588 2589 when Function_Table_1 => 2590 return Get_Table (T1, J, K); 2591 2592 when Function_Table_2 => 2593 return Get_Table (T2, J, K); 2594 2595 when Graph_Table => 2596 return Get_Graph (J); 2597 end case; 2598 end Value; 2599 2600end GNAT.Perfect_Hash_Generators; 2601