forked from lirm/aeron-go
/
reader.go
83 lines (65 loc) · 2.63 KB
/
reader.go
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/*
Copyright 2016 Stanislav Liberman
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 term
import (
"github.com/lirm/aeron-go/aeron/atomic"
"github.com/lirm/aeron-go/aeron/logbuffer"
"github.com/lirm/aeron-go/aeron/util"
)
// Read will attempt to read the next frame from the term and invoke the callback if successful.
// Method will return a tuple of new term offset and number of fragments read
//
//go:norace
func Read(termBuffer *atomic.Buffer, termOffset int32, handler FragmentHandler, fragmentLimit int,
header *logbuffer.Header) (int32, int) {
capacity := termBuffer.Capacity()
var fragmentsRead int
for fragmentsRead < fragmentLimit && termOffset < capacity {
frameLength := logbuffer.GetFrameLength(termBuffer, termOffset)
if frameLength <= 0 {
break
}
fragmentOffset := termOffset
termOffset += util.AlignInt32(frameLength, logbuffer.FrameAlignment)
if !logbuffer.IsPaddingFrame(termBuffer, fragmentOffset) {
header.Wrap(termBuffer.Ptr(), termBuffer.Capacity())
header.SetOffset(fragmentOffset)
handler(termBuffer, fragmentOffset+logbuffer.DataFrameHeader.Length,
frameLength-logbuffer.DataFrameHeader.Length, header)
fragmentsRead++
}
}
return termOffset, fragmentsRead
}
// BoundedRead will attempt to read frames from the term up to the specified offsetLimit.
// Method will return a tuple of new term offset and number of fragments read
func BoundedRead(termBuffer *atomic.Buffer, termOffset int32, offsetLimit int32, handler FragmentHandler,
fragmentLimit int, header *logbuffer.Header) (int32, int) {
var fragmentsRead int
for fragmentsRead < fragmentLimit && termOffset < offsetLimit {
frameLength := logbuffer.GetFrameLength(termBuffer, termOffset)
if frameLength <= 0 {
break
}
fragmentOffset := termOffset
termOffset += util.AlignInt32(frameLength, logbuffer.FrameAlignment)
if !logbuffer.IsPaddingFrame(termBuffer, fragmentOffset) {
header.Wrap(termBuffer.Ptr(), termBuffer.Capacity())
header.SetOffset(fragmentOffset)
handler(termBuffer, fragmentOffset+logbuffer.DataFrameHeader.Length,
frameLength-logbuffer.DataFrameHeader.Length, header)
fragmentsRead++
}
}
return termOffset, fragmentsRead
}