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Don't be too strict when checking the compression ratio (sf.net

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feature request #1596111).
This commit is contained in:
Markus F.X.J. Oberhumer 2006-11-20 09:40:46 +01:00
parent 9e65692b69
commit 4dfe9d52e9
2 changed files with 20 additions and 22 deletions
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41
src/packer.cpp
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@ -274,41 +274,38 @@ bool Packer::compress(upx_bytep in, upx_bytep out,
#endif
bool Packer::checkCompressionRatio(unsigned u_len, unsigned c_len) const
bool Packer::checkDefaultCompressionRatio(unsigned u_len, unsigned c_len) const
{
assert((int)u_len > 0);
assert((int)c_len > 0);
#if 1
if (c_len + 512 >= u_len) // min. 512 bytes gain
return false;
if (c_len >= u_len - u_len / 8) // min. 12.5% gain
return false;
#else
if (c_len >= u_len)
return false;
#endif
unsigned gain = u_len - c_len;
if (gain < 512) // need at least 512 bytes gain
return false;
#if 1
if (gain >= 4096) // ok if we have 4096 bytes gain
return true;
if (c_len >= u_len - u_len / 8) // ok if we have 12.5% gain
return true;
return false;
#else
return true;
#endif
}
bool Packer::checkCompressionRatio(unsigned u_len, unsigned c_len) const
{
return checkDefaultCompressionRatio(u_len, c_len);
}
bool Packer::checkFinalCompressionRatio(const OutputFile *fo) const
{
const unsigned u_len = file_size;
const unsigned c_len = fo->getBytesWritten();
assert((int)u_len > 0);
assert((int)c_len > 0);
if (c_len + 4096 <= u_len) // ok if we have 4096 bytes gain
return true;
if (c_len + 512 >= u_len) // min. 512 bytes gain
return false;
if (c_len >= u_len - u_len / 8) // min. 12.5% gain
return false;
return true;
return checkDefaultCompressionRatio(u_len, c_len);
}

1
src/packer.h
View File

@ -171,6 +171,7 @@ protected:
const upx_compress_config_t *cconf = NULL);
virtual void decompress(const upx_bytep in, upx_bytep out,
bool verify_checksum = true, Filter *ft = NULL);
virtual bool checkDefaultCompressionRatio(unsigned u_len, unsigned c_len) const;
virtual bool checkCompressionRatio(unsigned u_len, unsigned c_len) const;
virtual bool checkFinalCompressionRatio(const OutputFile *fo) const;