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Commit | Line | Data |
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c6f26b48 ET |
1 | /* |
2 | * Copyright (C) the libgit2 contributors. All rights reserved. | |
3 | * | |
4 | * This file is part of libgit2, distributed under the GNU GPL v2 with | |
5 | * a Linking Exception. For full terms see the included COPYING file. | |
6 | */ | |
7 | ||
8 | #include <zlib.h> | |
9 | ||
10 | #include "zstream.h" | |
11 | #include "buffer.h" | |
12 | ||
d9b04d78 RB |
13 | #define ZSTREAM_BUFFER_SIZE (1024 * 1024) |
14 | #define ZSTREAM_BUFFER_MIN_EXTRA 8 | |
c6f26b48 | 15 | |
d9b04d78 | 16 | static int zstream_seterr(git_zstream *zs) |
c6f26b48 | 17 | { |
d9b04d78 RB |
18 | if (zs->zerr == Z_OK || zs->zerr == Z_STREAM_END) |
19 | return 0; | |
20 | ||
21 | if (zs->zerr == Z_MEM_ERROR) | |
c6f26b48 | 22 | giterr_set_oom(); |
d9b04d78 RB |
23 | else if (zs->z.msg) |
24 | giterr_set(GITERR_ZLIB, zs->z.msg); | |
c6f26b48 ET |
25 | else |
26 | giterr_set(GITERR_ZLIB, "Unknown compression error"); | |
27 | ||
28 | return -1; | |
29 | } | |
30 | ||
31 | int git_zstream_init(git_zstream *zstream) | |
32 | { | |
d9b04d78 RB |
33 | zstream->zerr = deflateInit(&zstream->z, Z_DEFAULT_COMPRESSION); |
34 | return zstream_seterr(zstream); | |
c6f26b48 ET |
35 | } |
36 | ||
d9b04d78 | 37 | void git_zstream_free(git_zstream *zstream) |
c6f26b48 | 38 | { |
d9b04d78 RB |
39 | deflateEnd(&zstream->z); |
40 | } | |
c6f26b48 | 41 | |
d9b04d78 RB |
42 | void git_zstream_reset(git_zstream *zstream) |
43 | { | |
44 | deflateReset(&zstream->z); | |
45 | zstream->in = NULL; | |
46 | zstream->in_len = 0; | |
47 | zstream->zerr = Z_STREAM_END; | |
48 | } | |
c6f26b48 | 49 | |
d9b04d78 RB |
50 | int git_zstream_set_input(git_zstream *zstream, const void *in, size_t in_len) |
51 | { | |
52 | zstream->in = in; | |
53 | zstream->in_len = in_len; | |
54 | zstream->zerr = Z_OK; | |
55 | return 0; | |
56 | } | |
c6f26b48 | 57 | |
d9b04d78 RB |
58 | bool git_zstream_done(git_zstream *zstream) |
59 | { | |
60 | return (!zstream->in_len && zstream->zerr == Z_STREAM_END); | |
c6f26b48 ET |
61 | } |
62 | ||
d9b04d78 | 63 | size_t git_zstream_suggest_output_len(git_zstream *zstream) |
52a8a130 | 64 | { |
d9b04d78 RB |
65 | if (zstream->in_len > ZSTREAM_BUFFER_SIZE) |
66 | return ZSTREAM_BUFFER_SIZE; | |
67 | else if (zstream->in_len > ZSTREAM_BUFFER_MIN_EXTRA) | |
68 | return zstream->in_len; | |
69 | else | |
70 | return ZSTREAM_BUFFER_MIN_EXTRA; | |
52a8a130 ET |
71 | } |
72 | ||
d9b04d78 | 73 | int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream) |
c6f26b48 | 74 | { |
d9b04d78 RB |
75 | int zflush = Z_FINISH; |
76 | size_t out_remain = *out_len; | |
77 | ||
78 | while (out_remain > 0 && zstream->zerr != Z_STREAM_END) { | |
79 | size_t out_queued, in_queued, out_used, in_used; | |
80 | ||
81 | /* set up in data */ | |
82 | zstream->z.next_in = (Bytef *)zstream->in; | |
83 | zstream->z.avail_in = (uInt)zstream->in_len; | |
84 | if ((size_t)zstream->z.avail_in != zstream->in_len) { | |
85 | zstream->z.avail_in = INT_MAX; | |
86 | zflush = Z_NO_FLUSH; | |
87 | } else { | |
88 | zflush = Z_FINISH; | |
89 | } | |
90 | in_queued = (size_t)zstream->z.avail_in; | |
91 | ||
92 | /* set up out data */ | |
93 | zstream->z.next_out = out; | |
94 | zstream->z.avail_out = (uInt)out_remain; | |
95 | if ((size_t)zstream->z.avail_out != out_remain) | |
96 | zstream->z.avail_out = INT_MAX; | |
97 | out_queued = (size_t)zstream->z.avail_out; | |
98 | ||
99 | /* compress next chunk */ | |
100 | zstream->zerr = deflate(&zstream->z, zflush); | |
8606f33b | 101 | |
d9b04d78 RB |
102 | if (zstream->zerr == Z_STREAM_ERROR) |
103 | return zstream_seterr(zstream); | |
104 | ||
105 | out_used = (out_queued - zstream->z.avail_out); | |
106 | out_remain -= out_used; | |
107 | out = ((char *)out) + out_used; | |
108 | ||
109 | in_used = (in_queued - zstream->z.avail_in); | |
110 | zstream->in_len -= in_used; | |
111 | zstream->in += in_used; | |
112 | } | |
113 | ||
114 | /* either we finished the input or we did not flush the data */ | |
115 | assert(zstream->in_len > 0 || zflush == Z_FINISH); | |
116 | ||
117 | /* set out_size to number of bytes actually written to output */ | |
118 | *out_len = *out_len - out_remain; | |
119 | ||
120 | return 0; | |
c6f26b48 ET |
121 | } |
122 | ||
123 | int git_zstream_deflatebuf(git_buf *out, const void *in, size_t in_len) | |
124 | { | |
d9b04d78 | 125 | git_zstream zs = GIT_ZSTREAM_INIT; |
c6f26b48 ET |
126 | int error = 0; |
127 | ||
d9b04d78 | 128 | if ((error = git_zstream_init(&zs)) < 0) |
1cb5a811 | 129 | return error; |
c6f26b48 | 130 | |
d9b04d78 RB |
131 | if ((error = git_zstream_set_input(&zs, in, in_len)) < 0) |
132 | goto done; | |
c6f26b48 | 133 | |
d9b04d78 RB |
134 | while (!git_zstream_done(&zs)) { |
135 | size_t step = git_zstream_suggest_output_len(&zs), written; | |
c6f26b48 | 136 | |
4aa664ae | 137 | if ((error = git_buf_grow_by(out, step)) < 0) |
d9b04d78 | 138 | goto done; |
c6f26b48 | 139 | |
d9b04d78 | 140 | written = out->asize - out->size; |
c6f26b48 | 141 | |
d9b04d78 RB |
142 | if ((error = git_zstream_get_output( |
143 | out->ptr + out->size, &written, &zs)) < 0) | |
144 | goto done; | |
145 | ||
146 | out->size += written; | |
d9b04d78 | 147 | } |
c6f26b48 | 148 | |
19459b1e RB |
149 | /* NULL terminate for consistency if possible */ |
150 | if (out->size < out->asize) | |
151 | out->ptr[out->size] = '\0'; | |
152 | ||
d9b04d78 RB |
153 | done: |
154 | git_zstream_free(&zs); | |
c6f26b48 ET |
155 | return error; |
156 | } |