Upgrade to 0.12

[github/fretlink/terraform-provider-statuscake.git] / vendor / golang.org / x / net / http2 / hpack / huffman.go

diff --git a/vendor/golang.org/x/net/http2/hpack/huffman.go b/vendor/golang.org/x/net/http2/hpack/huffman.go
index 8850e3946770ea09203ddb3ea15d4c818e5eeea0..b412a96c5043b1b96e217fa534cd82daa052f549 100644 (file)
--- a/vendor/golang.org/x/net/http2/hpack/huffman.go
+++ b/vendor/golang.org/x/net/http2/hpack/huffman.go
@@ -47,6 +47,7 @@ var ErrInvalidHuffman = errors.New("hpack: invalid Huffman-encoded data")
 // If maxLen is greater than 0, attempts to write more to buf than
 // maxLen bytes will return ErrStringLength.
 func huffmanDecode(buf *bytes.Buffer, maxLen int, v []byte) error {
+       rootHuffmanNode := getRootHuffmanNode()
        n := rootHuffmanNode
        // cur is the bit buffer that has not been fed into n.
        // cbits is the number of low order bits in cur that are valid.
@@ -106,7 +107,7 @@ func huffmanDecode(buf *bytes.Buffer, maxLen int, v []byte) error {
 
 type node struct {
        // children is non-nil for internal nodes
-       children []*node
+       children *[256]*node
 
        // The following are only valid if children is nil:
        codeLen uint8 // number of bits that led to the output of sym
@@ -114,22 +115,31 @@ type node struct {
 }
 
 func newInternalNode() *node {
-       return &node{children: make([]*node, 256)}
+       return &node{children: new([256]*node)}
 }
 
-var rootHuffmanNode = newInternalNode()
+var (
+       buildRootOnce       sync.Once
+       lazyRootHuffmanNode *node
+)
+
+func getRootHuffmanNode() *node {
+       buildRootOnce.Do(buildRootHuffmanNode)
+       return lazyRootHuffmanNode
+}
 
-func init() {
+func buildRootHuffmanNode() {
        if len(huffmanCodes) != 256 {
                panic("unexpected size")
        }
+       lazyRootHuffmanNode = newInternalNode()
        for i, code := range huffmanCodes {
                addDecoderNode(byte(i), code, huffmanCodeLen[i])
        }
 }
 
 func addDecoderNode(sym byte, code uint32, codeLen uint8) {
-       cur := rootHuffmanNode
+       cur := lazyRootHuffmanNode
        for codeLen > 8 {
                codeLen -= 8
                i := uint8(code >> codeLen)