Diff

Differences From Artifact [1bc0c5d728]:

To Artifact [43e7f751ed]:


26
27
28
29
30
31
32
33
34
35
36
37
38

39
40

41
42

43
44
45
46
47
48
49
50


51
52
53
54

55
56
57

58
59
60
61
62
63
64
65
66
67
68

69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
26
27
28
29
30
31
32

33




34
35

36


37
38
39

40




41
42




43



44











45











46
47
48
49
50
51
52







-

-
-
-
-
+

-
+
-
-
+


-

-
-
-
-
+
+
-
-
-
-
+
-
-
-
+
-
-
-
-
-
-
-
-
-
-
-
+
-
-
-
-
-
-
-
-
-
-
-







// Returns an io.Writer implementation that wraps the provided io.Writer
// and compresses data according to the predictor algorithm
//
// It can buffer data as the predictor mandates 8-byte blocks with a header.
// A call with no data will force a flush.
func Compressor(writer io.Writer) io.Writer {
	var ctx context
	ctx.input = make([]byte, 0, 8)

	// Forward declaration as it is required for recursion
	var write iou.WriterFunc

	write = func(data []byte) (int, error) {
	return iou.SizedWriter(iou.WriterFunc(func(data []byte) (int, error) {
		var (
			blockSize    int = 8
			blockSize  int = 8
			bufferLength int = len(ctx.input)
			datalength   int = len(data)
			datalength int = len(data)
		)

		// Force a flush if we are called with no data to write
		if datalength == 0 {
			// Nothing to flush if the buffer is empty though
			if len(ctx.input) == 0 {
				return 0, nil
			}
			return 0, nil
		}
			// We can't have more than 7 bytes in the buffer so this is safe
			data, datalength = ctx.input, len(ctx.input)
			blockSize, bufferLength = datalength, 0
		}


		// Check if there are pending bytes in the buffer
		if datalength < blockSize || bufferLength > 0 {
		if datalength < blockSize {

			// If the current buffer + new data can fit into a block
			if (datalength + bufferLength) <= blockSize {
				ctx.input = append(ctx.input, data...)

				// Flush the block if the buffer fills it
				if len(ctx.input) == blockSize {
					return write(nil)
				}
				// ... otherwise just return
				return datalength, nil
			blockSize = datalength
			}

			// The current buffer + new data overflow the block size
			// Complete the block, flush it ...
			ctx.input = append(ctx.input, data[:blockSize-bufferLength]...)
			if c, err := write(nil); err != nil {
				return c, err
			}
			// ... and stage the rest of the data in the buffer
			ctx.input = append(ctx.input, data[blockSize-bufferLength:]...)
			return datalength, nil
		}

		var buf []byte = make([]byte, 1, blockSize+1)
		for block := 0; block < datalength/blockSize; block++ {
			for i := 0; i < blockSize; i++ {
				var current byte = data[(block*blockSize)+i]
				if ctx.table[ctx.hash] == current {
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113

114
115
116
117
118
119
120
121
122
64
65
66
67
68
69
70







71

72


73
74
75
76
77
78
79







-
-
-
-
-
-
-

-
+
-
-







				return (block * blockSize) + c, err
			}

			// Reset the flags and buffer for the next iteration
			buf, buf[0] = buf[:1], 0
		}

		if remaining := datalength % blockSize; remaining > 0 {
			ctx.input = ctx.input[:remaining]
			copy(ctx.input, data[datalength-remaining:])
		} else {
			ctx.input = ctx.input[:0]
		}

		return datalength, nil
	}
	}), 8)

	return write
}

// Returns an io.Reader implementation that wraps the provided io.Reader
// and decompresses data according to the predictor algorithm
func Decompressor(reader io.Reader) io.Reader {
	var ctx context
	ctx.input = make([]byte, 0, 8)