go-gitdiff/gitdiff/binary_reader.go at master · bluekeyes/go-gitdiff · GitHub

History

56 lines (51 loc) · 1.47 KB

Raw

package gitdiff

import (

"bytes"

"compress/zlib"

"fmt"

"io"

)

// binaryReader reads the compressed raw data in a binary fragment,

// decompressing it and checking it against the expected size. Clients should

// read until it returns an error or io.EOF.

type binaryReader struct {

r *io.LimitedReader

c io.Closer

size int64

raw []byte

}

func newBinaryReader(f *BinaryFragment) io.Reader {

return &binaryReader{

raw: f.RawData,

size: f.Size,

}

func (r *binaryReader) Read(p []byte) (int, error) {

// Defer initialization of the zlib reader so that we report any header

// errors from Read() instead of when creating the binaryReader. This

// allows clients to use io.ReadAll() directly with BinaryFragment.Data().

if r.r == nil {

zr, err := zlib.NewReader(bytes.NewReader(r.raw))

if err != nil {

return 0, err

}

r.r = &io.LimitedReader{R: zr, N: r.size + 1}

r.c = zr

}

n, err := r.r.Read(p)

if err == io.EOF {

// If we reached the "end", first check that we read the correct amount

// of data. On an exact read, the limit reader has one byte remaining.

switch {

case r.r.N > 1:

return n, fmt.Errorf("incorrect inflated size: expected %d bytes, received %d", r.size, r.size-(r.r.N-1))

case r.r.N < 1:

return n, fmt.Errorf("incorrect inflated size: expected %d bytes, received more", r.size)

}

// Then check that the zlib checksum is valid by closing the reader

if err := r.c.Close(); err != nil {

return n, err

}

return n, err

}

go-gitdiff/gitdiff/binary_reader.go at master · bluekeyes/go-gitdiff · GitHub

Expand file tree

Breadcrumbs

binary_reader.go

Latest commit

History

Breadcrumbs

binary_reader.go

File metadata and controls