1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Mike Olson. 7 * 8 * %sccs.include.redist.c% 9 */ 10 11 #if defined(LIBC_SCCS) && !defined(lint) 12 static char sccsid[] = "@(#)bt_conv.c 5.7 (Berkeley) 02/14/93"; 13 #endif /* LIBC_SCCS and not lint */ 14 15 #include <sys/param.h> 16 17 #include <stdio.h> 18 19 #include <db.h> 20 #include "btree.h" 21 22 static void kdswap __P((PAGE *)); 23 24 /* 25 * __BT_BPGIN, __BT_BPGOUT -- 26 * Convert host-specific number layout to/from the host-independent 27 * format stored on disk. 28 * 29 * Parameters: 30 * t: tree 31 * pg: page number 32 * h: page to convert 33 */ 34 void 35 __bt_pgin(t, pg, p) 36 void *t; 37 pgno_t pg; 38 void *p; 39 { 40 PAGE *h; 41 42 if (((BTREE *)t)->bt_lorder == BYTE_ORDER) 43 return; 44 45 h = p; 46 BLSWAP(h->pgno); 47 BLSWAP(h->prevpg); 48 BLSWAP(h->nextpg); 49 BLSWAP(h->flags); 50 BSSWAP(h->lower); 51 BSSWAP(h->upper); 52 kdswap(h); 53 } 54 55 void 56 __bt_pgout(t, pg, p) 57 void *t; 58 pgno_t pg; 59 void *p; 60 { 61 PAGE *h; 62 63 if (((BTREE *)t)->bt_lorder == BYTE_ORDER) 64 return; 65 66 h = p; 67 kdswap(h); 68 BLSWAP(h->pgno); 69 BLSWAP(h->prevpg); 70 BLSWAP(h->nextpg); 71 BLSWAP(h->flags); 72 BSSWAP(h->lower); 73 BSSWAP(h->upper); 74 } 75 76 /* 77 * KDSWAP -- Actually swap the bytes on the page. 78 * 79 * Parameters: 80 * h: page to convert 81 * 82 * Warnings: 83 * Everywhere else in the code, the pgno_t and indx_t types are 84 * opaque. These routines know what they really are. 85 */ 86 static void 87 kdswap(h) 88 PAGE *h; 89 { 90 register int i, top; 91 register char *p; /* Really void, thanks ANSI! */ 92 u_char flags; 93 94 top = NEXTINDEX(h); 95 switch (h->flags & P_TYPE) { 96 case P_BINTERNAL: 97 for (i = 0; i < top; i++) { 98 BSSWAP(h->linp[i]); 99 p = (char *)GETBINTERNAL(h, i); 100 BLPSWAP(p); 101 p += sizeof(size_t); 102 BLPSWAP(p); 103 p += sizeof(pgno_t); 104 if (*(u_char *)p & P_BIGKEY) { 105 p += sizeof(u_char); 106 BLPSWAP(p); 107 p += sizeof(pgno_t); 108 BLPSWAP(p); 109 } 110 } 111 break; 112 case P_BLEAF: 113 for (i = 0; i < top; i++) { 114 BSSWAP(h->linp[i]); 115 p = (char *)GETBLEAF(h, i); 116 BLPSWAP(p); 117 p += sizeof(size_t); 118 BLPSWAP(p); 119 p += sizeof(size_t); 120 flags = *(u_char *)p; 121 if (flags & (P_BIGKEY | P_BIGDATA)) { 122 p += sizeof(u_char); 123 if (flags & P_BIGKEY) { 124 BLPSWAP(p); 125 p += sizeof(pgno_t); 126 BLPSWAP(p); 127 } 128 if (flags & P_BIGDATA) { 129 p += sizeof(size_t); 130 BLPSWAP(p); 131 p += sizeof(pgno_t); 132 BLPSWAP(p); 133 } 134 } 135 } 136 break; 137 } 138 } 139