mirror of https://github.com/hrfee/jfa-go.git
67 lines
1.3 KiB
Go
67 lines
1.3 KiB
Go
// Package linecache provides a writer that stores n lines of text at once, overwriting old content as it reaches its capacity. Its contents can be read from with a String() method.
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package linecache
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import (
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"strings"
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"sync"
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)
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// LineCache provides an io.Writer that stores a fixed number of lines of text.
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type LineCache struct {
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count int
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lines [][]byte
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current int
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lock *sync.Mutex
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}
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// NewLineCache returns a new line cache of capacity (n) lines.
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func NewLineCache(n int) *LineCache {
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return &LineCache{
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current: 0,
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count: n,
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lines: make([][]byte, n),
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lock: &sync.Mutex{},
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}
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}
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// Write writes a given byte array to the cache.
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func (l *LineCache) Write(p []byte) (n int, err error) {
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l.lock.Lock()
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defer l.lock.Unlock()
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lines := strings.Split(string(p), "\n")
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for _, line := range lines {
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if string(line) == "" {
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continue
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}
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if l.current == l.count {
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l.current = 0
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}
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l.lines[l.current] = []byte(line)
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l.current++
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}
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n = len(p)
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return
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}
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// String returns a string representation of the cache contents.
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func (l *LineCache) String() string {
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i := 0
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if l.lines[l.count-1] != nil && l.current != l.count {
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i = l.current
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}
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out := ""
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for {
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if l.lines[i] == nil {
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return out
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}
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out += string(l.lines[i]) + "\n"
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i++
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if i == l.current {
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return out
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}
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if i == l.count {
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i = 0
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}
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}
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}
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