peridot/vendor/github.com/antchfx/xmlquery/cached_reader.go

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2022-07-07 20:11:50 +00:00
package xmlquery
import (
"bufio"
)
type cachedReader struct {
buffer *bufio.Reader
cache []byte
cacheCap int
cacheLen int
caching bool
}
func newCachedReader(r *bufio.Reader) *cachedReader {
return &cachedReader{
buffer: r,
cache: make([]byte, 4096),
cacheCap: 4096,
cacheLen: 0,
caching: false,
}
}
func (c *cachedReader) StartCaching() {
c.cacheLen = 0
c.caching = true
}
func (c *cachedReader) ReadByte() (byte, error) {
if !c.caching {
return c.buffer.ReadByte()
}
b, err := c.buffer.ReadByte()
if err != nil {
return b, err
}
if c.cacheLen < c.cacheCap {
c.cache[c.cacheLen] = b
c.cacheLen++
}
return b, err
}
func (c *cachedReader) Cache() []byte {
return c.cache[:c.cacheLen]
}
func (c *cachedReader) StopCaching() {
c.caching = false
}
func (c *cachedReader) Read(p []byte) (int, error) {
n, err := c.buffer.Read(p)
if err != nil {
return n, err
}
if c.caching && c.cacheLen < c.cacheCap {
for i := 0; i < n; i++ {
c.cache[c.cacheLen] = p[i]
c.cacheLen++
if c.cacheLen >= c.cacheCap {
break
}
}
}
return n, err
}