1 /** @file flint_alldocspostlist.cc
2 * @brief A PostList which iterates over all documents in a FlintDatabase.
3 */
4 /* Copyright (C) 2006,2007,2008,2009 Olly Betts
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include <config.h>
22 #include "flint_alldocspostlist.h"
23
24 #include <string>
25
26 #include "debuglog.h"
27 #include "flint_database.h"
28 #include "str.h"
29
30 using namespace std;
31
32 Xapian::doccount
get_termfreq() const33 FlintAllDocsPostList::get_termfreq() const
34 {
35 return doccount;
36 }
37
38 Xapian::docid
get_docid() const39 FlintAllDocsPostList::get_docid() const
40 {
41 return current_did;
42 }
43
44 Xapian::termcount
get_doclength() const45 FlintAllDocsPostList::get_doclength() const
46 {
47 LOGCALL(DB, Xapian::termcount, "FlintAllDocsPostList::get_doclength", NO_ARGS);
48 Assert(current_did);
49
50 cursor->read_tag();
51
52 if (cursor->current_tag.empty()) RETURN(0);
53
54 const char * pos = cursor->current_tag.data();
55 const char * end = pos + cursor->current_tag.size();
56
57 flint_doclen_t doclen;
58 if (!F_unpack_uint(&pos, end, &doclen)) {
59 const char *msg;
60 if (pos == 0) {
61 msg = "Too little data for doclen in termlist";
62 } else {
63 msg = "Overflowed value for doclen in termlist";
64 }
65 throw Xapian::DatabaseCorruptError(msg);
66 }
67
68 RETURN(doclen);
69 }
70
71 Xapian::termcount
get_wdf() const72 FlintAllDocsPostList::get_wdf() const
73 {
74 LOGCALL(DB, Xapian::termcount, "FlintAllDocsPostList::get_wdf", NO_ARGS);
75 Assert(current_did);
76 RETURN(1);
77 }
78
79 PostList *
read_did_from_current_key()80 FlintAllDocsPostList::read_did_from_current_key()
81 {
82 LOGCALL(DB, PostList *, "FlintAllDocsPostList::read_did_from_current_key", NO_ARGS);
83 const string & key = cursor->current_key;
84 const char * pos = key.data();
85 const char * end = pos + key.size();
86 if (!F_unpack_uint_preserving_sort(&pos, end, ¤t_did)) {
87 const char *msg;
88 if (pos == 0) {
89 msg = "Too little data in termlist key";
90 } else {
91 msg = "Overflowed value in termlist key";
92 }
93 throw Xapian::DatabaseCorruptError(msg);
94 }
95
96 // Return NULL to help the compiler tail-call optimise our callers.
97 RETURN(NULL);
98 }
99
100 PostList *
next(Xapian::weight)101 FlintAllDocsPostList::next(Xapian::weight /*w_min*/)
102 {
103 LOGCALL(DB, PostList *, "FlintAllDocsPostList::next", Literal("/*w_min*/"));
104 Assert(!at_end());
105 if (!cursor->next()) RETURN(NULL);
106 RETURN(read_did_from_current_key());
107 }
108
109 PostList *
skip_to(Xapian::docid did,Xapian::weight)110 FlintAllDocsPostList::skip_to(Xapian::docid did, Xapian::weight /*w_min*/)
111 {
112 LOGCALL(DB, PostList *, "FlintAllDocsPostList::skip_to", did | Literal("/*w_min*/"));
113
114 if (did <= current_did || at_end()) RETURN(NULL);
115
116 if (cursor->find_entry_ge(F_pack_uint_preserving_sort(did))) {
117 // The exact docid that was asked for exists.
118 current_did = did;
119 RETURN(NULL);
120 }
121 if (cursor->after_end()) RETURN(NULL);
122
123 RETURN(read_did_from_current_key());
124 }
125
126 bool
at_end() const127 FlintAllDocsPostList::at_end() const {
128 LOGCALL(DB, bool, "FlintAllDocsPostList::at_end", NO_ARGS);
129 RETURN(cursor->after_end());
130 }
131
132 string
get_description() const133 FlintAllDocsPostList::get_description() const
134 {
135 string desc = "FlintAllDocsPostList(did=";
136 desc += str(current_did);
137 desc += ",doccount=";
138 desc += str(doccount);
139 desc += ')';
140 return desc;
141 }
142