mirror of
https://github.com/love2d/love.git
synced 2026-08-13 17:10:54 +02:00
Added gzip support to love.math.compress and love.math.decompress.
This commit is contained in:
Alex Szpakowski
+126
-24
@@ -39,8 +39,11 @@ class LZ4Compressor : public Compressor
|
||||
{
|
||||
public:
|
||||
|
||||
char *compress(const char *data, size_t dataSize, int level, size_t &compressedSize) override
|
||||
char *compress(Format format, const char *data, size_t dataSize, int level, size_t &compressedSize) override
|
||||
{
|
||||
if (format != FORMAT_LZ4)
|
||||
throw love::Exception("Invalid format (expecting LZ4)");
|
||||
|
||||
if (dataSize > LZ4_MAX_INPUT_SIZE)
|
||||
throw love::Exception("Data is too large for LZ4 compressor.");
|
||||
|
||||
@@ -99,8 +102,11 @@ public:
|
||||
return compressedbytes;
|
||||
}
|
||||
|
||||
char *decompress(const char *data, size_t dataSize, size_t &decompressedSize) override
|
||||
char *decompress(Format format, const char *data, size_t dataSize, size_t &decompressedSize) override
|
||||
{
|
||||
if (format != FORMAT_LZ4)
|
||||
throw love::Exception("Invalid format (expecting LZ4)");
|
||||
|
||||
const size_t headersize = sizeof(uint32);
|
||||
char *rawbytes = nullptr;
|
||||
|
||||
@@ -154,23 +160,111 @@ public:
|
||||
return rawbytes;
|
||||
}
|
||||
|
||||
Compressor::Format getFormat() const override { return FORMAT_LZ4; }
|
||||
bool isSupported(Format format) const override
|
||||
{
|
||||
return format == FORMAT_LZ4;
|
||||
}
|
||||
|
||||
}; // LZ4Compressor
|
||||
|
||||
|
||||
class zlibCompressor : public Compressor
|
||||
{
|
||||
private:
|
||||
|
||||
// The following three functions are mostly copied from the zlib source
|
||||
// (compressBound, compress2, and uncompress), but modified to support both
|
||||
// zlib and gzip.
|
||||
|
||||
uLong zlibCompressBound(Format format, uLong sourceLen)
|
||||
{
|
||||
uLong size = sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + (sourceLen >> 25) + 13;
|
||||
|
||||
// The gzip header is slightly larger than the zlib header.
|
||||
if (format == FORMAT_GZIP)
|
||||
size += 18 - 6;
|
||||
|
||||
return size;
|
||||
}
|
||||
|
||||
int zlibCompress(Format format, Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level)
|
||||
{
|
||||
z_stream stream = {};
|
||||
|
||||
stream.next_in = (Bytef *) source;
|
||||
stream.avail_in = (uInt) sourceLen;
|
||||
|
||||
stream.next_out = dest;
|
||||
stream.avail_out = (uInt) (*destLen);
|
||||
|
||||
int windowbits = 15;
|
||||
if (format == FORMAT_GZIP)
|
||||
windowbits += 16; // This tells zlib to use a gzip header.
|
||||
|
||||
int err = deflateInit2(&stream, level, Z_DEFLATED, windowbits, 8, Z_DEFAULT_STRATEGY);
|
||||
|
||||
if (err != Z_OK)
|
||||
return err;
|
||||
|
||||
err = deflate(&stream, Z_FINISH);
|
||||
|
||||
if (err != Z_STREAM_END)
|
||||
{
|
||||
deflateEnd(&stream);
|
||||
return err == Z_OK ? Z_BUF_ERROR : err;
|
||||
}
|
||||
|
||||
*destLen = stream.total_out;
|
||||
|
||||
return deflateEnd(&stream);
|
||||
}
|
||||
|
||||
int zlibDecompress(Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
|
||||
{
|
||||
z_stream stream = {};
|
||||
|
||||
stream.next_in = (Bytef *) source;
|
||||
stream.avail_in = (uInt) sourceLen;
|
||||
|
||||
stream.next_out = dest;
|
||||
stream.avail_out = (uInt) (*destLen);
|
||||
|
||||
// 15 is the default. Adding 32 makes zlib auto-detect the header type.
|
||||
int windowbits = 15 + 32;
|
||||
|
||||
int err = inflateInit2(&stream, windowbits);
|
||||
|
||||
if (err != Z_OK)
|
||||
return err;
|
||||
|
||||
err = inflate(&stream, Z_FINISH);
|
||||
|
||||
if (err != Z_STREAM_END)
|
||||
{
|
||||
inflateEnd(&stream);
|
||||
if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0))
|
||||
return Z_DATA_ERROR;
|
||||
return err;
|
||||
}
|
||||
|
||||
*destLen = stream.total_out;
|
||||
|
||||
return inflateEnd(&stream);
|
||||
}
|
||||
|
||||
public:
|
||||
|
||||
char *compress(const char *data, size_t dataSize, int level, size_t &compressedSize) override
|
||||
char *compress(Format format, const char *data, size_t dataSize, int level, size_t &compressedSize) override
|
||||
{
|
||||
if (!isSupported(format))
|
||||
throw love::Exception("Invalid format (expecting zlib or gzip)");
|
||||
|
||||
if (level < 0)
|
||||
level = Z_DEFAULT_COMPRESSION;
|
||||
else if (level > 9)
|
||||
level = 9;
|
||||
|
||||
uLong maxsize = compressBound((uLong) dataSize);
|
||||
uLong maxsize = zlibCompressBound(format, (uLong) dataSize);
|
||||
char *compressedbytes = nullptr;
|
||||
|
||||
try
|
||||
@@ -183,18 +277,18 @@ public:
|
||||
}
|
||||
|
||||
uLongf destlen = maxsize;
|
||||
int status = compress2((Bytef *) compressedbytes, &destlen, (const Bytef *) data, (uLong) dataSize, level);
|
||||
int status = zlibCompress(format, (Bytef *) compressedbytes, &destlen, (const Bytef *) data, (uLong) dataSize, level);
|
||||
|
||||
if (status != Z_OK)
|
||||
{
|
||||
delete[] compressedbytes;
|
||||
throw love::Exception("Could not zlib-compress data.");
|
||||
throw love::Exception("Could not zlib/gzip-compress data.");
|
||||
}
|
||||
|
||||
// We allocated space for the maximum possible amount of data, but the
|
||||
// actual compressed size might be much smaller, so we should shrink the
|
||||
// data buffer if so.
|
||||
if ((double) maxsize / (double) destlen >= 1.2)
|
||||
if ((double) maxsize / (double) destlen >= 1.3)
|
||||
{
|
||||
char *cbytes = new (std::nothrow) char[destlen];
|
||||
if (cbytes)
|
||||
@@ -209,8 +303,11 @@ public:
|
||||
return compressedbytes;
|
||||
}
|
||||
|
||||
char *decompress(const char *data, size_t dataSize, size_t &decompressedSize) override
|
||||
char *decompress(Format format, const char *data, size_t dataSize, size_t &decompressedSize) override
|
||||
{
|
||||
if (!isSupported(format))
|
||||
throw love::Exception("Invalid format (expecting zlib or gzip)");
|
||||
|
||||
char *rawbytes = nullptr;
|
||||
|
||||
// We might know the output size before decompression. If not, we guess.
|
||||
@@ -229,7 +326,7 @@ public:
|
||||
}
|
||||
|
||||
uLongf destLen = (uLongf) rawsize;
|
||||
int status = uncompress((Bytef *) rawbytes, &destLen, (const Bytef *) data, (uLong) dataSize);
|
||||
int status = zlibDecompress((Bytef *) rawbytes, &destLen, (const Bytef *) data, (uLong) dataSize);
|
||||
|
||||
if (status == Z_OK)
|
||||
{
|
||||
@@ -240,7 +337,7 @@ public:
|
||||
{
|
||||
// For any error other than "not enough room", throw an exception.
|
||||
delete[] rawbytes;
|
||||
throw love::Exception("Could not decompress zlib-compressed data.");
|
||||
throw love::Exception("Could not decompress zlib/gzip-compressed data.");
|
||||
}
|
||||
|
||||
// Not enough room in the output buffer: try again with a larger size.
|
||||
@@ -251,23 +348,27 @@ public:
|
||||
return rawbytes;
|
||||
}
|
||||
|
||||
Compressor::Format getFormat() const override { return FORMAT_ZLIB; }
|
||||
bool isSupported(Format format) const override
|
||||
{
|
||||
return format == FORMAT_ZLIB || format == FORMAT_GZIP;
|
||||
}
|
||||
|
||||
}; // zlibCompressor
|
||||
|
||||
|
||||
Compressor *Compressor::Create(Format format)
|
||||
Compressor *Compressor::getCompressor(Format format)
|
||||
{
|
||||
switch (format)
|
||||
static LZ4Compressor lz4compressor;
|
||||
static zlibCompressor zlibcompressor;
|
||||
|
||||
Compressor *compressors[] = {&lz4compressor, &zlibcompressor};
|
||||
|
||||
for (Compressor *c : compressors)
|
||||
{
|
||||
case FORMAT_LZ4:
|
||||
return new LZ4Compressor;
|
||||
case FORMAT_ZLIB:
|
||||
return new zlibCompressor;
|
||||
default:
|
||||
throw love::Exception("Invalid compressor format.");
|
||||
return nullptr;
|
||||
if (c->isSupported(format))
|
||||
return c;
|
||||
}
|
||||
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
bool Compressor::getConstant(const char *in, Format &out)
|
||||
@@ -282,8 +383,9 @@ bool Compressor::getConstant(Format in, const char *&out)
|
||||
|
||||
StringMap<Compressor::Format, Compressor::FORMAT_MAX_ENUM>::Entry Compressor::formatEntries[] =
|
||||
{
|
||||
{"lz4", Compressor::FORMAT_LZ4},
|
||||
{"zlib", Compressor::FORMAT_ZLIB},
|
||||
{"lz4", FORMAT_LZ4},
|
||||
{"zlib", FORMAT_ZLIB},
|
||||
{"gzip", FORMAT_GZIP},
|
||||
};
|
||||
|
||||
StringMap<Compressor::Format, Compressor::FORMAT_MAX_ENUM> Compressor::formatNames(Compressor::formatEntries, sizeof(Compressor::formatEntries));
|
||||
|
||||
Reference in New Issue
Block a user