diff options
Diffstat (limited to 'zlib.c')
| -rw-r--r-- | zlib.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/zlib.c b/zlib.c new file mode 100644 index 0000000000..3c63d480c7 --- /dev/null +++ b/zlib.c @@ -0,0 +1,251 @@ +/* + * zlib wrappers to make sure we don't silently miss errors + * at init time. + */ +#include "cache.h" + +static const char *zerr_to_string(int status) +{ + switch (status) { + case Z_MEM_ERROR: + return "out of memory"; + case Z_VERSION_ERROR: + return "wrong version"; + case Z_NEED_DICT: + return "needs dictionary"; + case Z_DATA_ERROR: + return "data stream error"; + case Z_STREAM_ERROR: + return "stream consistency error"; + default: + return "unknown error"; + } +} + +/* + * avail_in and avail_out in zlib are counted in uInt, which typically + * limits the size of the buffer we can use to 4GB when interacting + * with zlib in a single call to inflate/deflate. + */ +/* #define ZLIB_BUF_MAX ((uInt)-1) */ +#define ZLIB_BUF_MAX ((uInt) 1024 * 1024 * 1024) /* 1GB */ +static inline uInt zlib_buf_cap(unsigned long len) +{ + return (ZLIB_BUF_MAX < len) ? ZLIB_BUF_MAX : len; +} + +static void zlib_pre_call(git_zstream *s) +{ + s->z.next_in = s->next_in; + s->z.next_out = s->next_out; + s->z.total_in = s->total_in; + s->z.total_out = s->total_out; + s->z.avail_in = zlib_buf_cap(s->avail_in); + s->z.avail_out = zlib_buf_cap(s->avail_out); +} + +static void zlib_post_call(git_zstream *s) +{ + unsigned long bytes_consumed; + unsigned long bytes_produced; + + bytes_consumed = s->z.next_in - s->next_in; + bytes_produced = s->z.next_out - s->next_out; + if (s->z.total_out != s->total_out + bytes_produced) + die("BUG: total_out mismatch"); + if (s->z.total_in != s->total_in + bytes_consumed) + die("BUG: total_in mismatch"); + + s->total_out = s->z.total_out; + s->total_in = s->z.total_in; + s->next_in = s->z.next_in; + s->next_out = s->z.next_out; + s->avail_in -= bytes_consumed; + s->avail_out -= bytes_produced; +} + +void git_inflate_init(git_zstream *strm) +{ + int status; + + zlib_pre_call(strm); + status = inflateInit(&strm->z); + zlib_post_call(strm); + if (status == Z_OK) + return; + die("inflateInit: %s (%s)", zerr_to_string(status), + strm->z.msg ? strm->z.msg : "no message"); +} + +void git_inflate_init_gzip_only(git_zstream *strm) +{ + /* + * Use default 15 bits, +16 is to accept only gzip and to + * yield Z_DATA_ERROR when fed zlib format. + */ + const int windowBits = 15 + 16; + int status; + + zlib_pre_call(strm); + status = inflateInit2(&strm->z, windowBits); + zlib_post_call(strm); + if (status == Z_OK) + return; + die("inflateInit2: %s (%s)", zerr_to_string(status), + strm->z.msg ? strm->z.msg : "no message"); +} + +void git_inflate_end(git_zstream *strm) +{ + int status; + + zlib_pre_call(strm); + status = inflateEnd(&strm->z); + zlib_post_call(strm); + if (status == Z_OK) + return; + error("inflateEnd: %s (%s)", zerr_to_string(status), + strm->z.msg ? strm->z.msg : "no message"); +} + +int git_inflate(git_zstream *strm, int flush) +{ + int status; + + for (;;) { + zlib_pre_call(strm); + /* Never say Z_FINISH unless we are feeding everything */ + status = inflate(&strm->z, + (strm->z.avail_in != strm->avail_in) + ? 0 : flush); + if (status == Z_MEM_ERROR) + die("inflate: out of memory"); + zlib_post_call(strm); + + /* + * Let zlib work another round, while we can still + * make progress. + */ + if ((strm->avail_out && !strm->z.avail_out) && + (status == Z_OK || status == Z_BUF_ERROR)) + continue; + break; + } + + switch (status) { + /* Z_BUF_ERROR: normal, needs more space in the output buffer */ + case Z_BUF_ERROR: + case Z_OK: + case Z_STREAM_END: + return status; + default: + break; + } + error("inflate: %s (%s)", zerr_to_string(status), + strm->z.msg ? strm->z.msg : "no message"); + return status; +} + +#if defined(NO_DEFLATE_BOUND) || ZLIB_VERNUM < 0x1200 +#define deflateBound(c,s) ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11) +#endif + +unsigned long git_deflate_bound(git_zstream *strm, unsigned long size) +{ + return deflateBound(&strm->z, size); +} + +void git_deflate_init(git_zstream *strm, int level) +{ + int status; + + zlib_pre_call(strm); + status = deflateInit(&strm->z, level); + zlib_post_call(strm); + if (status == Z_OK) + return; + die("deflateInit: %s (%s)", zerr_to_string(status), + strm->z.msg ? strm->z.msg : "no message"); +} + +void git_deflate_init_gzip(git_zstream *strm, int level) +{ + /* + * Use default 15 bits, +16 is to generate gzip header/trailer + * instead of the zlib wrapper. + */ + const int windowBits = 15 + 16; + int status; + + zlib_pre_call(strm); + status = deflateInit2(&strm->z, level, + Z_DEFLATED, windowBits, + 8, Z_DEFAULT_STRATEGY); + zlib_post_call(strm); + if (status == Z_OK) + return; + die("deflateInit2: %s (%s)", zerr_to_string(status), + strm->z.msg ? strm->z.msg : "no message"); +} + +void git_deflate_end(git_zstream *strm) +{ + int status; + + zlib_pre_call(strm); + status = deflateEnd(&strm->z); + zlib_post_call(strm); + if (status == Z_OK) + return; + error("deflateEnd: %s (%s)", zerr_to_string(status), + strm->z.msg ? strm->z.msg : "no message"); +} + +int git_deflate_end_gently(git_zstream *strm) +{ + int status; + + zlib_pre_call(strm); + status = deflateEnd(&strm->z); + zlib_post_call(strm); + return status; +} + +int git_deflate(git_zstream *strm, int flush) +{ + int status; + + for (;;) { + zlib_pre_call(strm); + + /* Never say Z_FINISH unless we are feeding everything */ + status = deflate(&strm->z, + (strm->z.avail_in != strm->avail_in) + ? 0 : flush); + if (status == Z_MEM_ERROR) + die("deflate: out of memory"); + zlib_post_call(strm); + + /* + * Let zlib work another round, while we can still + * make progress. + */ + if ((strm->avail_out && !strm->z.avail_out) && + (status == Z_OK || status == Z_BUF_ERROR)) + continue; + break; + } + + switch (status) { + /* Z_BUF_ERROR: normal, needs more space in the output buffer */ + case Z_BUF_ERROR: + case Z_OK: + case Z_STREAM_END: + return status; + default: + break; + } + error("deflate: %s (%s)", zerr_to_string(status), + strm->z.msg ? strm->z.msg : "no message"); + return status; +} |