add io.ByteReader.
add testing/iotest package.
make bufio return error on short write.
R=r
DELTA=423 (208 added, 154 deleted, 61 changed)
OCL=28997
CL=28999
diff --git a/src/lib/io/bytebuffer.go b/src/lib/io/bytebuffer.go
index c862818..921ddb1 100644
--- a/src/lib/io/bytebuffer.go
+++ b/src/lib/io/bytebuffer.go
@@ -42,13 +42,17 @@
// Truncate discards all but the first n unread bytes from the buffer.
// It is an error to call b.Truncate(n) with n > b.Len().
func (b *ByteBuffer) Truncate(n int) {
+ if n == 0 {
+ // Reuse buffer space.
+ b.off = 0;
+ }
b.buf = b.buf[0 : b.off + n];
}
// Reset resets the buffer so it has no content.
// b.Reset() is the same as b.Truncate(0).
func (b *ByteBuffer) Reset() {
- b.buf = b.buf[0 : b.off];
+ b.Truncate(0);
}
// Write appends the contents of p to the buffer. The return
diff --git a/src/lib/io/io.go b/src/lib/io/io.go
index 70c82d5..91b6ffd 100644
--- a/src/lib/io/io.go
+++ b/src/lib/io/io.go
@@ -185,3 +185,29 @@
}
return written, err
}
+
+// A ByteReader satisfies Reads by consuming data from a slice of bytes.
+// Clients can call NewByteReader to create one or wrap pointers
+// to their own slices: r := ByteReader{&data}.
+type ByteReader struct {
+ Data *[]byte
+}
+
+func (r ByteReader) Read(p []byte) (int, os.Error) {
+ n := len(p);
+ b := r.Data;
+ if n > len(b) {
+ n = len(b);
+ }
+ for i := 0; i < n; i++ {
+ p[i] = b[i];
+ }
+ *b = b[n:len(b)];
+ return n, nil;
+}
+
+// NewByteReader returns a new ByteReader reading from data.
+func NewByteReader(data []byte) ByteReader {
+ return ByteReader{ &data };
+}
+
