Overview
Comment: | Additional fixes and code simplification for MinReader |
---|---|
Downloads: | Tarball | ZIP archive | SQL archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
70896f73e95a9811868d697c2c2f59eb |
User & Date: | spaskalev on 2014-12-23 18:39:59 |
Other Links: | manifest | tags |
Context
2014-12-23
| ||
18:52 | Renamed MinReader to BlockReader. The later is now used by predictor's decompressor to simplify the code and deal away with the need for internal buffering. check-in: 38f8e62c81 user: spaskalev tags: trunk | |
18:39 | Additional fixes and code simplification for MinReader check-in: 70896f73e9 user: spaskalev tags: trunk | |
14:27 | minReader fixes check-in: 4195e7817d user: spaskalev tags: trunk | |
Changes
Modified src/0dev.org/ioutil/ioutil.go from [4d4fd7d642] to [3d22f83cbe].
1
2
3
4
5
6
7
8
9
10
11
..
22
23
24
25
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
|
// Package ioutil contains various constructs for io operations package ioutil import ( "io" ) // An function alias type that implements io.Writer type WriterFunc func([]byte) (int, error) // Delegates the call to the WriterFunc while implementing io.Writer ................................................................................ } // Returns a reader that will delegate calls to Read(...) while ensuring // that the output buffer will never be smaller than the required size func MinReader(reader io.Reader, size int) io.Reader { var buffer []byte = make([]byte, 0, size) return ReaderFunc(func(output []byte) (readCount int, e error) { var ( bufferLength int = len(buffer) err error ) start: // Reply with the buffered data if there is any if bufferLength > 0 { readCount = copy(output, buffer) if readCount < bufferLength { // Advance the data in the buffer buffer = buffer[:copy(buffer, buffer[readCount:])] } else { // Clear the buffer buffer = buffer[:0] } // Stage any error for returning e, err = err, nil return readCount, e } // Delegate if the buffer is empty and the destination buffer is large enough if len(output) >= size { return reader.Read(output[:len(output)/size]) } // Extend the buffer up to the desired size and perform a Read buffer = buffer[:size] readCount, err = reader.Read(buffer) // Size the buffer down to the read data size and restart buffer = buffer[:readCount] bufferLength = len(buffer) if bufferLength > 0 { goto start } // Stage any error for returning e, err = err, nil return 0, e }) } |
>
|
|
|
>
>
<
>
<
|
|
<
<
>
|
|
|
|
>
>
>
|
>
|
<
|
|
<
<
>
>
>
<
<
|
|
1
2
3
4
5
6
7
8
9
10
11
12
..
23
24
25
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
|
// Package ioutil contains various constructs for io operations package ioutil import ( //"fmt" "io" ) // An function alias type that implements io.Writer type WriterFunc func([]byte) (int, error) // Delegates the call to the WriterFunc while implementing io.Writer ................................................................................ } // Returns a reader that will delegate calls to Read(...) while ensuring // that the output buffer will never be smaller than the required size func MinReader(reader io.Reader, size int) io.Reader { var buffer []byte = make([]byte, 0, size) return ReaderFunc(func(output []byte) (int, error) { var ( readCount int err error ) start: //fmt.Println("Requesting read with length ", len(output), "buffer's length is ", len(buffer)) // Reply with the buffered data if there is any if len(buffer) > 0 { readCount = copy(output, buffer) // Advance the data in the buffer buffer = buffer[:copy(buffer, buffer[readCount:])] //fmt.Println("After buffer read - buffer lenght is", len(buffer)) if len(buffer) == 0 { return readCount, err } // Do not propagate an error until the buffer is exhausted return readCount, nil } // Delegate if the buffer is empty and the destination buffer is large enough if len(output) >= size { //fmt.Println("Delegating read for output length ", len(output), " and size ", size) return reader.Read(output[:(len(output)/size)*size]) } // Perform a read into the buffer readCount, err = reader.Read(buffer[:size]) // Size the buffer down to the read data size and restart buffer = buffer[:readCount] //fmt.Println("Read into buffer: ", len(buffer), "bytes") if len(buffer) > 0 { goto start } return 0, err }) } |