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add more comments for flush

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This commit is contained in:
jinjunzh 2022-07-06 23:31:22 -04:00
parent 4cdc660406
commit 3422c0479d
1 changed files with 16 additions and 4 deletions
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20
src/Compression/ICompressionCodec.h
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@ -26,11 +26,18 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t * data, size_t size);
class ICompressionCodec : private boost::noncopyable
{
public:
/// Three kinds of codec mode:
/// Synchronous mode which is commonly used by default;
/// --- For the codec with HW decompressor, it means submit request to HW and busy wait till complete.
/// Asynchronous mode which required HW decompressor support;
/// --- For the codec with HW decompressor, it means submit request to HW and return immeditately.
/// --- Must be used in pair with flushAsynchronousDecompressRequests.
/// SoftwareFallback mode is exclusively defined for the codec with HW decompressor, enable its capability of "fallback to SW codec".
enum class CodecMode
{
Synchronous, //synchronous request by default;
Asynchronous, //asynchronous request, must be used in pair with flushAsynchronousDecompressRequests;
SoftwareFallback //Fallback to SW decompressor;
Synchronous,
Asynchronous,
SoftwareFallback
};
virtual ~ICompressionCodec() = default;
@ -65,7 +72,12 @@ public:
decompressMode = mode;
}
/// Flush all asynchronous request for decompression
/// Flush result for previous asynchronous decompression requests.
/// This function must be called following several requests offload to HW.
/// To make sure asynchronous results have been flushed into target buffer completely.
/// Meanwhile, source and target buffer for decompression should not be overwritten until this function execute completely.
/// Otherwise it would conflict with HW offloading and cause exception.
/// For QPL deflate, it support the maximum number of requests equal to DeflateJobHWPool::jobPoolSize
void flushAsynchronousDecompressRequests();
/// Number of bytes, that will be used to compress uncompressed_size bytes with current codec