mirror of https://github.com/perkeep/perkeep.git
97 lines
2.1 KiB
Go
97 lines
2.1 KiB
Go
/*
|
|
Copyright 2011 Google 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 main
|
|
|
|
import (
|
|
"bufio"
|
|
"fmt"
|
|
"io"
|
|
"log"
|
|
"os"
|
|
"strings"
|
|
|
|
"camlistore.org/pkg/rollsum"
|
|
)
|
|
|
|
type span struct {
|
|
from, to int64
|
|
bits int
|
|
children []span
|
|
}
|
|
|
|
func showSplits(file string) {
|
|
f, err := os.Open(file)
|
|
if err != nil {
|
|
panic(err.Error())
|
|
}
|
|
bufr := bufio.NewReader(f)
|
|
|
|
spans := []span{}
|
|
rs := rollsum.New()
|
|
n := int64(0)
|
|
last := n
|
|
|
|
for {
|
|
c, err := bufr.ReadByte()
|
|
if err != nil {
|
|
if err == io.EOF {
|
|
if n != last {
|
|
spans = append(spans, span{from: last, to: n})
|
|
}
|
|
break
|
|
}
|
|
panic(err.Error())
|
|
}
|
|
n++
|
|
rs.Roll(c)
|
|
if rs.OnSplit() {
|
|
bits := rs.Bits()
|
|
sliceFrom := len(spans)
|
|
for sliceFrom > 0 && spans[sliceFrom-1].bits < bits {
|
|
sliceFrom--
|
|
}
|
|
nCopy := len(spans) - sliceFrom
|
|
var children []span
|
|
if nCopy > 0 {
|
|
children = make([]span, nCopy)
|
|
nCopied := copy(children, spans[sliceFrom:])
|
|
if nCopied != nCopy {
|
|
panic("n wrong")
|
|
}
|
|
spans = spans[:sliceFrom]
|
|
}
|
|
spans = append(spans, span{from: last, to: n, bits: bits, children: children})
|
|
|
|
log.Printf("split at %d (after %d), bits=%d", n, n-last, bits)
|
|
last = n
|
|
}
|
|
}
|
|
|
|
var dumpSpans func(s []span, indent int)
|
|
dumpSpans = func(s []span, indent int) {
|
|
in := strings.Repeat(" ", indent)
|
|
for _, sp := range s {
|
|
fmt.Printf("%sfrom=%d, to=%d (len %d) bits=%d\n", in, sp.from, sp.to, sp.to-sp.from, sp.bits)
|
|
if len(sp.children) > 0 {
|
|
dumpSpans(sp.children, indent+4)
|
|
}
|
|
}
|
|
}
|
|
dumpSpans(spans, 0)
|
|
fmt.Printf("\n\nNOTE NOTE NOTE: the camdebug tool hasn't been updated to use the splitting policy from pkg/schema/filewriter.go.")
|
|
}
|