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author | Edward Thomson <ethomson@edwardthomson.com> | 2017-12-17 18:44:02 +0000 |
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committer | Edward Thomson <ethomson@edwardthomson.com> | 2018-02-01 16:50:30 -0800 |
commit | 6155e06b74c7eaeac6dfdc32e0d71f212be32f42 (patch) | |
tree | feee84bdf25a26bc5c6b81cc510cf7c361b262a6 | |
parent | b1e66bfc6cd5068dd0b1695e44d28b6c586c8e2e (diff) | |
download | libgit2-6155e06b74c7eaeac6dfdc32e0d71f212be32f42.tar.gz |
zstream: introduce a single chunk reader
Introduce `get_output_chunk` that will inflate/deflate all the available
input buffer into the output buffer. `get_output` will call
`get_output_chunk` in a loop, while other consumers can use it to
inflate only a piece of the data.
-rw-r--r-- | src/zstream.c | 85 | ||||
-rw-r--r-- | src/zstream.h | 6 |
2 files changed, 55 insertions, 36 deletions
diff --git a/src/zstream.c b/src/zstream.c index 963c9a344..affa55653 100644 --- a/src/zstream.c +++ b/src/zstream.c @@ -87,9 +87,52 @@ size_t git_zstream_suggest_output_len(git_zstream *zstream) return ZSTREAM_BUFFER_MIN_EXTRA; } +int git_zstream_get_output_chunk( + void *out, size_t *out_len, git_zstream *zstream) +{ + size_t in_queued, in_used, out_queued; + + /* set up input data */ + zstream->z.next_in = (Bytef *)zstream->in; + + /* feed as much data to zlib as it can consume, at most UINT_MAX */ + if (zstream->in_len > UINT_MAX) { + zstream->z.avail_in = UINT_MAX; + zstream->flush = Z_NO_FLUSH; + } else { + zstream->z.avail_in = (uInt)zstream->in_len; + zstream->flush = Z_FINISH; + } + in_queued = (size_t)zstream->z.avail_in; + + /* set up output data */ + zstream->z.next_out = out; + zstream->z.avail_out = (uInt)*out_len; + + if ((size_t)zstream->z.avail_out != *out_len) + zstream->z.avail_out = UINT_MAX; + out_queued = (size_t)zstream->z.avail_out; + + /* compress next chunk */ + if (zstream->type == GIT_ZSTREAM_INFLATE) + zstream->zerr = inflate(&zstream->z, zstream->flush); + else + zstream->zerr = deflate(&zstream->z, zstream->flush); + + if (zstream_seterr(zstream)) + return -1; + + in_used = (in_queued - zstream->z.avail_in); + zstream->in_len -= in_used; + zstream->in += in_used; + + *out_len = (out_queued - zstream->z.avail_out); + + return 0; +} + int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream) { - int zflush = Z_FINISH; size_t out_remain = *out_len; if (zstream->in_len && zstream->zerr == Z_STREAM_END) { @@ -98,47 +141,17 @@ int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream) } while (out_remain > 0 && zstream->zerr != Z_STREAM_END) { - size_t out_queued, in_queued, out_used, in_used; + size_t out_written = out_remain; - /* set up in data */ - zstream->z.next_in = (Bytef *)zstream->in; - zstream->z.avail_in = (uInt)zstream->in_len; - - if ((size_t)zstream->z.avail_in != zstream->in_len) { - zstream->z.avail_in = UINT_MAX; - zflush = Z_NO_FLUSH; - } else { - zflush = Z_FINISH; - } - in_queued = (size_t)zstream->z.avail_in; - - /* set up out data */ - zstream->z.next_out = out; - zstream->z.avail_out = (uInt)out_remain; - if ((size_t)zstream->z.avail_out != out_remain) - zstream->z.avail_out = UINT_MAX; - out_queued = (size_t)zstream->z.avail_out; - - /* compress next chunk */ - if (zstream->type == GIT_ZSTREAM_INFLATE) - zstream->zerr = inflate(&zstream->z, zflush); - else - zstream->zerr = deflate(&zstream->z, zflush); - - if (zstream_seterr(zstream)) + if (git_zstream_get_output_chunk(out, &out_written, zstream) < 0) return -1; - out_used = (out_queued - zstream->z.avail_out); - out_remain -= out_used; - out = ((char *)out) + out_used; - - in_used = (in_queued - zstream->z.avail_in); - zstream->in_len -= in_used; - zstream->in += in_used; + out_remain -= out_written; + out = ((char *)out) + out_written; } /* either we finished the input or we did not flush the data */ - assert(zstream->in_len > 0 || zflush == Z_FINISH); + assert(zstream->in_len > 0 || zstream->flush == Z_FINISH); /* set out_size to number of bytes actually written to output */ *out_len = *out_len - out_remain; diff --git a/src/zstream.h b/src/zstream.h index fcc4a3148..cfe2b395f 100644 --- a/src/zstream.h +++ b/src/zstream.h @@ -23,6 +23,7 @@ typedef struct { git_zstream_t type; const char *in; size_t in_len; + int flush; int zerr; } git_zstream; @@ -35,6 +36,11 @@ int git_zstream_set_input(git_zstream *zstream, const void *in, size_t in_len); size_t git_zstream_suggest_output_len(git_zstream *zstream); +/* get as much output as is available in the input buffer */ +int git_zstream_get_output_chunk( + void *out, size_t *out_len, git_zstream *zstream); + +/* get all the output from the entire input buffer */ int git_zstream_get_output(void *out, size_t *out_len, git_zstream *zstream); bool git_zstream_done(git_zstream *zstream); |