githaven-fork/vendor/github.com/blevesearch/zapx/v12/count.go
2021-02-28 18:08:33 -05:00

62 lines
1.7 KiB
Go
Vendored

// Copyright (c) 2017 Couchbase, Inc.
//
// 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 zap
import (
"hash/crc32"
"io"
segment "github.com/blevesearch/scorch_segment_api/v2"
)
// CountHashWriter is a wrapper around a Writer which counts the number of
// bytes which have been written and computes a crc32 hash
type CountHashWriter struct {
w io.Writer
crc uint32
n int
s segment.StatsReporter
}
// NewCountHashWriter returns a CountHashWriter which wraps the provided Writer
func NewCountHashWriter(w io.Writer) *CountHashWriter {
return &CountHashWriter{w: w}
}
func NewCountHashWriterWithStatsReporter(w io.Writer, s segment.StatsReporter) *CountHashWriter {
return &CountHashWriter{w: w, s: s}
}
// Write writes the provided bytes to the wrapped writer and counts the bytes
func (c *CountHashWriter) Write(b []byte) (int, error) {
n, err := c.w.Write(b)
c.crc = crc32.Update(c.crc, crc32.IEEETable, b[:n])
c.n += n
if c.s != nil {
c.s.ReportBytesWritten(uint64(n))
}
return n, err
}
// Count returns the number of bytes written
func (c *CountHashWriter) Count() int {
return c.n
}
// Sum32 returns the CRC-32 hash of the content written to this writer
func (c *CountHashWriter) Sum32() uint32 {
return c.crc
}