1 c35a7943 2018-07-12 stsp /*
  2 c35a7943 2018-07-12 stsp  * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
  3 c35a7943 2018-07-12 stsp  *
  4 c35a7943 2018-07-12 stsp  * Permission to use, copy, modify, and distribute this software for any
  5 c35a7943 2018-07-12 stsp  * purpose with or without fee is hereby granted, provided that the above
  6 c35a7943 2018-07-12 stsp  * copyright notice and this permission notice appear in all copies.
  7 c35a7943 2018-07-12 stsp  *
  8 c35a7943 2018-07-12 stsp  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  9 c35a7943 2018-07-12 stsp  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 10 c35a7943 2018-07-12 stsp  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 11 c35a7943 2018-07-12 stsp  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 12 c35a7943 2018-07-12 stsp  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 13 c35a7943 2018-07-12 stsp  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 14 c35a7943 2018-07-12 stsp  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 15 c35a7943 2018-07-12 stsp  */
 16 c35a7943 2018-07-12 stsp 
 17 c35a7943 2018-07-12 stsp #include <sys/queue.h>
 18 c35a7943 2018-07-12 stsp #include <sys/stat.h>
 19 c35a7943 2018-07-12 stsp 
 20 c35a7943 2018-07-12 stsp #include <stdio.h>
 21 c35a7943 2018-07-12 stsp #include <stdlib.h>
 22 c35a7943 2018-07-12 stsp #include <sha1.h>
 23 c35a7943 2018-07-12 stsp #include <zlib.h>
 24 c35a7943 2018-07-12 stsp 
 25 c35a7943 2018-07-12 stsp #include "got_object.h"
 26 c35a7943 2018-07-12 stsp 
 27 c35a7943 2018-07-12 stsp #include "got_error.h"
 28 c35a7943 2018-07-12 stsp #include "got_lib_delta.h"
 29 c35a7943 2018-07-12 stsp #include "got_lib_inflate.h"
 30 c35a7943 2018-07-12 stsp #include "got_lib_object.h"
 31 c35a7943 2018-07-12 stsp #include "got_lib_diffoffset.h"
 32 c35a7943 2018-07-12 stsp 
 33 c35a7943 2018-07-12 stsp /*
 34 c35a7943 2018-07-12 stsp  * A line offset between an old file and a new file, derived from diff chunk
 35 c35a7943 2018-07-12 stsp  * header info @@ -old_lineno,old_length +new_lineno,new_length @@ in a diff
 36 c35a7943 2018-07-12 stsp  * with zero context lines (as in diff -U0 old-file new-file).
 37 c35a7943 2018-07-12 stsp  */
 38 c35a7943 2018-07-12 stsp struct got_diffoffset_chunk {
 39 c35a7943 2018-07-12 stsp 	int lineno;	/* first line which has shifted */
 40 c35a7943 2018-07-12 stsp 	int offset;	/* applies to subsequent lines until next chunk */
 41 c35a7943 2018-07-12 stsp 	SIMPLEQ_ENTRY(got_diffoffset_chunk) entry;
 42 c35a7943 2018-07-12 stsp };
 43 c35a7943 2018-07-12 stsp 
 44 c35a7943 2018-07-12 stsp static struct got_diffoffset_chunk *
 45 c35a7943 2018-07-12 stsp alloc_chunk(int lineno, int offset)
 46 c35a7943 2018-07-12 stsp {
 47 c35a7943 2018-07-12 stsp 	struct got_diffoffset_chunk *chunk;
 48 c35a7943 2018-07-12 stsp 
 49 c35a7943 2018-07-12 stsp 	chunk = calloc(1, sizeof(*chunk));
 50 c35a7943 2018-07-12 stsp 	if (chunk == NULL)
 51 c35a7943 2018-07-12 stsp 		return NULL;
 52 c35a7943 2018-07-12 stsp 
 53 c35a7943 2018-07-12 stsp 	chunk->lineno = lineno;
 54 c35a7943 2018-07-12 stsp 	chunk->offset = offset;
 55 c35a7943 2018-07-12 stsp 
 56 c35a7943 2018-07-12 stsp 	return chunk;
 57 c35a7943 2018-07-12 stsp }
 58 c35a7943 2018-07-12 stsp 
 59 c35a7943 2018-07-12 stsp const struct got_error *
 60 c35a7943 2018-07-12 stsp got_diffoffset_alloc(struct got_diffoffset_chunks **chunks)
 61 c35a7943 2018-07-12 stsp {
 62 c35a7943 2018-07-12 stsp 	const struct got_error *err = NULL;
 63 c35a7943 2018-07-12 stsp 	struct got_diffoffset_chunk *first;
 64 c35a7943 2018-07-12 stsp 
 65 c35a7943 2018-07-12 stsp 	first = alloc_chunk(0, 0);
 66 c35a7943 2018-07-12 stsp 	if (first == NULL)
 67 638f9024 2019-05-13 stsp 		return got_error_from_errno("alloc_chunk");
 68 c35a7943 2018-07-12 stsp 
 69 c35a7943 2018-07-12 stsp 	*chunks = calloc(1, sizeof(**chunks));
 70 c35a7943 2018-07-12 stsp 	if (*chunks == NULL) {
 71 638f9024 2019-05-13 stsp 		err = got_error_from_errno("calloc");
 72 c35a7943 2018-07-12 stsp 		free(first);
 73 c35a7943 2018-07-12 stsp 		return err;
 74 c35a7943 2018-07-12 stsp 	}
 75 c35a7943 2018-07-12 stsp 
 76 c35a7943 2018-07-12 stsp 	SIMPLEQ_INIT(*chunks);
 77 c35a7943 2018-07-12 stsp 	SIMPLEQ_INSERT_HEAD(*chunks, first, entry);
 78 c35a7943 2018-07-12 stsp 
 79 c35a7943 2018-07-12 stsp 	return NULL;
 80 c35a7943 2018-07-12 stsp }
 81 c35a7943 2018-07-12 stsp 
 82 c35a7943 2018-07-12 stsp void
 83 c35a7943 2018-07-12 stsp got_diffoffset_free(struct got_diffoffset_chunks *chunks)
 84 c35a7943 2018-07-12 stsp {
 85 c35a7943 2018-07-12 stsp 	struct got_diffoffset_chunk *chunk;
 86 c35a7943 2018-07-12 stsp 
 87 c35a7943 2018-07-12 stsp 	while (!SIMPLEQ_EMPTY(chunks)) {
 88 c35a7943 2018-07-12 stsp 		chunk = SIMPLEQ_FIRST(chunks);
 89 c35a7943 2018-07-12 stsp 		SIMPLEQ_REMOVE_HEAD(chunks, entry);
 90 c35a7943 2018-07-12 stsp 		free(chunk);
 91 c35a7943 2018-07-12 stsp 	}
 92 c35a7943 2018-07-12 stsp 	free(chunks);
 93 c35a7943 2018-07-12 stsp }
 94 c35a7943 2018-07-12 stsp 
 95 c35a7943 2018-07-12 stsp const struct got_error *
 96 c35a7943 2018-07-12 stsp got_diffoffset_add(struct got_diffoffset_chunks *chunks,
 97 c35a7943 2018-07-12 stsp     int old_lineno, int old_length, int new_lineno, int new_length)
 98 c35a7943 2018-07-12 stsp {
 99 c35a7943 2018-07-12 stsp 	struct got_diffoffset_chunk *chunk1, *chunk2;
100 c35a7943 2018-07-12 stsp 
101 c35a7943 2018-07-12 stsp 	chunk1 = alloc_chunk(old_lineno, new_lineno - old_lineno);
102 c35a7943 2018-07-12 stsp 	if (chunk1 == NULL)
103 638f9024 2019-05-13 stsp 		return got_error_from_errno("alloc_chunk");
104 c35a7943 2018-07-12 stsp 
105 c35a7943 2018-07-12 stsp 	chunk2 = alloc_chunk(old_lineno + old_length,
106 c35a7943 2018-07-12 stsp 	    new_lineno - old_lineno + new_length - old_length);
107 c35a7943 2018-07-12 stsp 	if (chunk2 == NULL) {
108 230a42bd 2019-05-11 jcs 		const struct got_error *err =
109 638f9024 2019-05-13 stsp 		    got_error_from_errno("alloc_chunk");
110 c35a7943 2018-07-12 stsp 		free(chunk1);
111 c35a7943 2018-07-12 stsp 		return err;
112 c35a7943 2018-07-12 stsp 	}
113 c35a7943 2018-07-12 stsp 
114 c35a7943 2018-07-12 stsp 	SIMPLEQ_INSERT_TAIL(chunks, chunk1, entry);
115 c35a7943 2018-07-12 stsp 	SIMPLEQ_INSERT_TAIL(chunks, chunk2, entry);
116 c35a7943 2018-07-12 stsp 	return NULL;
117 c35a7943 2018-07-12 stsp }
118 c35a7943 2018-07-12 stsp 
119 c35a7943 2018-07-12 stsp int
120 c35a7943 2018-07-12 stsp got_diffoffset_get(struct got_diffoffset_chunks *chunks, int lineno)
121 c35a7943 2018-07-12 stsp {
122 c35a7943 2018-07-12 stsp 	struct got_diffoffset_chunk *chunk, *prev;
123 c35a7943 2018-07-12 stsp 
124 c35a7943 2018-07-12 stsp 	prev = SIMPLEQ_FIRST(chunks);
125 c35a7943 2018-07-12 stsp 	SIMPLEQ_FOREACH(chunk, chunks, entry) {
126 c35a7943 2018-07-12 stsp 		if (chunk->lineno > lineno)
127 c35a7943 2018-07-12 stsp 			break;
128 c35a7943 2018-07-12 stsp 		prev = chunk;
129 c35a7943 2018-07-12 stsp 	}
130 c35a7943 2018-07-12 stsp 
131 c35a7943 2018-07-12 stsp 	return lineno + prev->offset;
132 c35a7943 2018-07-12 stsp }