diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/encoder.go')
-rw-r--r-- | vendor/github.com/klauspost/compress/zstd/encoder.go | 39 |
1 files changed, 37 insertions, 2 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/encoder.go b/vendor/github.com/klauspost/compress/zstd/encoder.go index e6b1d01c..65c6c36d 100644 --- a/vendor/github.com/klauspost/compress/zstd/encoder.go +++ b/vendor/github.com/klauspost/compress/zstd/encoder.go @@ -8,6 +8,7 @@ import ( "crypto/rand" "fmt" "io" + "math" rdebug "runtime/debug" "sync" @@ -528,8 +529,8 @@ func (e *Encoder) EncodeAll(src, dst []byte) []byte { // If a non-single block is needed the encoder will reset again. e.encoders <- enc }() - // Use single segments when above minimum window and below 1MB. - single := len(src) < 1<<20 && len(src) > MinWindowSize + // Use single segments when above minimum window and below window size. + single := len(src) <= e.o.windowSize && len(src) > MinWindowSize if e.o.single != nil { single = *e.o.single } @@ -639,3 +640,37 @@ func (e *Encoder) EncodeAll(src, dst []byte) []byte { } return dst } + +// MaxEncodedSize returns the expected maximum +// size of an encoded block or stream. +func (e *Encoder) MaxEncodedSize(size int) int { + frameHeader := 4 + 2 // magic + frame header & window descriptor + if e.o.dict != nil { + frameHeader += 4 + } + // Frame content size: + if size < 256 { + frameHeader++ + } else if size < 65536+256 { + frameHeader += 2 + } else if size < math.MaxInt32 { + frameHeader += 4 + } else { + frameHeader += 8 + } + // Final crc + if e.o.crc { + frameHeader += 4 + } + + // Max overhead is 3 bytes/block. + // There cannot be 0 blocks. + blocks := (size + e.o.blockSize) / e.o.blockSize + + // Combine, add padding. + maxSz := frameHeader + 3*blocks + size + if e.o.pad > 1 { + maxSz += calcSkippableFrame(int64(maxSz), int64(e.o.pad)) + } + return maxSz +} |