diff options
Diffstat (limited to 'common/hugio/hasBytesWriter.go')
-rw-r--r-- | common/hugio/hasBytesWriter.go | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/common/hugio/hasBytesWriter.go b/common/hugio/hasBytesWriter.go new file mode 100644 index 000000000..7b7d7a5d7 --- /dev/null +++ b/common/hugio/hasBytesWriter.go @@ -0,0 +1,57 @@ +// Copyright 2022 The Hugo Authors. All rights reserved. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package hugio + +import ( + "bytes" +) + +// HasBytesWriter is a writer that will set Match to true if the given pattern +// is found in the stream. +type HasBytesWriter struct { + Match bool + Pattern []byte + + i int + done bool + buff []byte +} + +func (h *HasBytesWriter) Write(p []byte) (n int, err error) { + if h.done { + return len(p), nil + } + + if len(h.buff) == 0 { + h.buff = make([]byte, len(h.Pattern)*2) + } + + for i := range p { + h.buff[h.i] = p[i] + h.i++ + if h.i == len(h.buff) { + // Shift left. + copy(h.buff, h.buff[len(h.buff)/2:]) + h.i = len(h.buff) / 2 + } + + if bytes.Contains(h.buff, h.Pattern) { + h.Match = true + h.done = true + return len(p), nil + } + } + + return len(p), nil +} |