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author | Serhiy Storchaka <storchaka@gmail.com> | 2018-01-20 14:42:44 (GMT) |
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committer | GitHub <noreply@github.com> | 2018-01-20 14:42:44 (GMT) |
commit | 1211c9a9897a174b7261ca258cabf289815a40d8 (patch) | |
tree | a43814a9172d44d64d7427d10249c816e5f4ef0e /Modules | |
parent | bd5c7d238c01b90fbfae8ea45b47bd601900abaf (diff) | |
download | cpython-1211c9a9897a174b7261ca258cabf289815a40d8.zip cpython-1211c9a9897a174b7261ca258cabf289815a40d8.tar.gz cpython-1211c9a9897a174b7261ca258cabf289815a40d8.tar.bz2 |
bpo-32503: Avoid creating too small frames in pickles. (#5127)
Diffstat (limited to 'Modules')
-rw-r--r-- | Modules/_pickle.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/Modules/_pickle.c b/Modules/_pickle.c index f8cbea1..f06a87d 100644 --- a/Modules/_pickle.c +++ b/Modules/_pickle.c @@ -119,8 +119,8 @@ enum { /* Prefetch size when unpickling (disabled on unpeekable streams) */ PREFETCH = 8192 * 16, + FRAME_SIZE_MIN = 4, FRAME_SIZE_TARGET = 64 * 1024, - FRAME_HEADER_SIZE = 9 }; @@ -949,13 +949,6 @@ _write_size64(char *out, size_t value) } } -static void -_Pickler_WriteFrameHeader(PicklerObject *self, char *qdata, size_t frame_len) -{ - qdata[0] = FRAME; - _write_size64(qdata + 1, frame_len); -} - static int _Pickler_CommitFrame(PicklerObject *self) { @@ -966,7 +959,14 @@ _Pickler_CommitFrame(PicklerObject *self) return 0; frame_len = self->output_len - self->frame_start - FRAME_HEADER_SIZE; qdata = PyBytes_AS_STRING(self->output_buffer) + self->frame_start; - _Pickler_WriteFrameHeader(self, qdata, frame_len); + if (frame_len >= FRAME_SIZE_MIN) { + qdata[0] = FRAME; + _write_size64(qdata + 1, frame_len); + } + else { + memmove(qdata, qdata + FRAME_HEADER_SIZE, frame_len); + self->output_len -= FRAME_HEADER_SIZE; + } self->frame_start = -1; return 0; } |