diff options
Diffstat (limited to 'src/pkg/io/ioutil/ioutil.go')
| -rw-r--r-- | src/pkg/io/ioutil/ioutil.go | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/src/pkg/io/ioutil/ioutil.go b/src/pkg/io/ioutil/ioutil.go index a38e48811..c322f49c2 100644 --- a/src/pkg/io/ioutil/ioutil.go +++ b/src/pkg/io/ioutil/ioutil.go @@ -34,15 +34,15 @@ func ReadFile(filename string) ([]byte, os.Error) { if err != nil && dir.Size < 2e9 { // Don't preallocate a huge buffer, just in case. n = dir.Size } - if n == 0 { - n = 1024 // No idea what's right, but zero isn't. - } + // Add a little extra in case Size is zero, and to avoid another allocation after + // Read has filled the buffer. + n += bytes.MinRead; // Pre-allocate the correct size of buffer, then set its size to zero. The // Buffer will read into the allocated space cheaply. If the size was wrong, // we'll either waste some space off the end or reallocate as needed, but // in the overwhelmingly common case we'll get it just right. - buf := bytes.NewBuffer(make([]byte, n)[0:0]); - _, err = io.Copy(buf, f); + buf := bytes.NewBuffer(make([]byte, 0, n)); + _, err = buf.ReadFrom(f); return buf.Bytes(), err; } |