gotosocial/vendor/github.com/ugorji/go/codec/writer.go
2023-02-25 12:12:40 +00:00

324 lines
6.3 KiB
Go

// Copyright (c) 2012-2020 Ugorji Nwoke. All rights reserved.
// Use of this source code is governed by a MIT license found in the LICENSE file.
package codec
import "io"
// encWriter abstracts writing to a byte array or to an io.Writer.
type encWriter interface {
writeb([]byte)
writestr(string)
writeqstr(string) // write string wrapped in quotes ie "..."
writen1(byte)
// add convenience functions for writing 2,4
writen2(byte, byte)
writen4([4]byte)
writen8([8]byte)
end()
}
// ---------------------------------------------
type bufioEncWriter struct {
w io.Writer
buf []byte
n int
b [16]byte // scratch buffer and padding (cache-aligned)
}
func (z *bufioEncWriter) reset(w io.Writer, bufsize int, blist *bytesFreelist) {
z.w = w
z.n = 0
if bufsize <= 0 {
bufsize = defEncByteBufSize
}
// bufsize must be >= 8, to accomodate writen methods (where n <= 8)
if bufsize <= 8 {
bufsize = 8
}
if cap(z.buf) < bufsize {
if len(z.buf) > 0 && &z.buf[0] != &z.b[0] {
blist.put(z.buf)
}
if len(z.b) > bufsize {
z.buf = z.b[:]
} else {
z.buf = blist.get(bufsize)
}
}
z.buf = z.buf[:cap(z.buf)]
}
func (z *bufioEncWriter) flushErr() (err error) {
n, err := z.w.Write(z.buf[:z.n])
z.n -= n
if z.n > 0 {
if err == nil {
err = io.ErrShortWrite
}
if n > 0 {
copy(z.buf, z.buf[n:z.n+n])
}
}
return err
}
func (z *bufioEncWriter) flush() {
halt.onerror(z.flushErr())
}
func (z *bufioEncWriter) writeb(s []byte) {
LOOP:
a := len(z.buf) - z.n
if len(s) > a {
z.n += copy(z.buf[z.n:], s[:a])
s = s[a:]
z.flush()
goto LOOP
}
z.n += copy(z.buf[z.n:], s)
}
func (z *bufioEncWriter) writestr(s string) {
// z.writeb(bytesView(s)) // inlined below
LOOP:
a := len(z.buf) - z.n
if len(s) > a {
z.n += copy(z.buf[z.n:], s[:a])
s = s[a:]
z.flush()
goto LOOP
}
z.n += copy(z.buf[z.n:], s)
}
func (z *bufioEncWriter) writeqstr(s string) {
// z.writen1('"')
// z.writestr(s)
// z.writen1('"')
if z.n+len(s)+2 > len(z.buf) {
z.flush()
}
setByteAt(z.buf, uint(z.n), '"')
// z.buf[z.n] = '"'
z.n++
LOOP:
a := len(z.buf) - z.n
if len(s)+1 > a {
z.n += copy(z.buf[z.n:], s[:a])
s = s[a:]
z.flush()
goto LOOP
}
z.n += copy(z.buf[z.n:], s)
setByteAt(z.buf, uint(z.n), '"')
// z.buf[z.n] = '"'
z.n++
}
func (z *bufioEncWriter) writen1(b1 byte) {
if 1 > len(z.buf)-z.n {
z.flush()
}
setByteAt(z.buf, uint(z.n), b1)
// z.buf[z.n] = b1
z.n++
}
func (z *bufioEncWriter) writen2(b1, b2 byte) {
if 2 > len(z.buf)-z.n {
z.flush()
}
setByteAt(z.buf, uint(z.n+1), b2)
setByteAt(z.buf, uint(z.n), b1)
// z.buf[z.n+1] = b2
// z.buf[z.n] = b1
z.n += 2
}
func (z *bufioEncWriter) writen4(b [4]byte) {
if 4 > len(z.buf)-z.n {
z.flush()
}
// setByteAt(z.buf, uint(z.n+3), b4)
// setByteAt(z.buf, uint(z.n+2), b3)
// setByteAt(z.buf, uint(z.n+1), b2)
// setByteAt(z.buf, uint(z.n), b1)
copy(z.buf[z.n:], b[:])
z.n += 4
}
func (z *bufioEncWriter) writen8(b [8]byte) {
if 8 > len(z.buf)-z.n {
z.flush()
}
copy(z.buf[z.n:], b[:])
z.n += 8
}
func (z *bufioEncWriter) endErr() (err error) {
if z.n > 0 {
err = z.flushErr()
}
return
}
// ---------------------------------------------
// bytesEncAppender implements encWriter and can write to an byte slice.
type bytesEncAppender struct {
b []byte
out *[]byte
}
func (z *bytesEncAppender) writeb(s []byte) {
z.b = append(z.b, s...)
}
func (z *bytesEncAppender) writestr(s string) {
z.b = append(z.b, s...)
}
func (z *bytesEncAppender) writeqstr(s string) {
z.b = append(append(append(z.b, '"'), s...), '"')
// z.b = append(z.b, '"')
// z.b = append(z.b, s...)
// z.b = append(z.b, '"')
}
func (z *bytesEncAppender) writen1(b1 byte) {
z.b = append(z.b, b1)
}
func (z *bytesEncAppender) writen2(b1, b2 byte) {
z.b = append(z.b, b1, b2)
}
func (z *bytesEncAppender) writen4(b [4]byte) {
z.b = append(z.b, b[:]...)
// z.b = append(z.b, b1, b2, b3, b4) // prevents inlining encWr.writen4
}
func (z *bytesEncAppender) writen8(b [8]byte) {
z.b = append(z.b, b[:]...)
// z.b = append(z.b, b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]) // prevents inlining encWr.writen4
}
func (z *bytesEncAppender) endErr() error {
*(z.out) = z.b
return nil
}
func (z *bytesEncAppender) reset(in []byte, out *[]byte) {
z.b = in[:0]
z.out = out
}
// --------------------------------------------------
type encWr struct {
wb bytesEncAppender
wf *bufioEncWriter
bytes bool // encoding to []byte
// MARKER: these fields below should belong directly in Encoder.
// we pack them here for space efficiency and cache-line optimization.
js bool // is json encoder?
be bool // is binary encoder?
c containerState
calls uint16
seq uint16 // sequencer (e.g. used by binc for symbols, etc)
}
// MARKER: manually inline bytesEncAppender.writenx/writeqstr methods,
// as calling them causes encWr.writenx/writeqstr methods to not be inlined (cost > 80).
//
// i.e. e.g. instead of writing z.wb.writen2(b1, b2), use z.wb.b = append(z.wb.b, b1, b2)
func (z *encWr) writeb(s []byte) {
if z.bytes {
z.wb.writeb(s)
} else {
z.wf.writeb(s)
}
}
func (z *encWr) writestr(s string) {
if z.bytes {
z.wb.writestr(s)
} else {
z.wf.writestr(s)
}
}
// MARKER: Add WriteStr to be called directly by generated code without a genHelper forwarding function.
// Go's inlining model adds cost for forwarding functions, preventing inlining (cost goes above 80 budget).
func (z *encWr) WriteStr(s string) {
if z.bytes {
z.wb.writestr(s)
} else {
z.wf.writestr(s)
}
}
func (z *encWr) writen1(b1 byte) {
if z.bytes {
z.wb.writen1(b1)
} else {
z.wf.writen1(b1)
}
}
func (z *encWr) writen2(b1, b2 byte) {
if z.bytes {
// MARKER: z.wb.writen2(b1, b2)
z.wb.b = append(z.wb.b, b1, b2)
} else {
z.wf.writen2(b1, b2)
}
}
func (z *encWr) writen4(b [4]byte) {
if z.bytes {
// MARKER: z.wb.writen4(b1, b2, b3, b4)
z.wb.b = append(z.wb.b, b[:]...)
// z.wb.writen4(b)
} else {
z.wf.writen4(b)
}
}
func (z *encWr) writen8(b [8]byte) {
if z.bytes {
// z.wb.b = append(z.wb.b, b[:]...)
z.wb.writen8(b)
} else {
z.wf.writen8(b)
}
}
func (z *encWr) writeqstr(s string) {
if z.bytes {
// MARKER: z.wb.writeqstr(s)
z.wb.b = append(append(append(z.wb.b, '"'), s...), '"')
} else {
z.wf.writeqstr(s)
}
}
func (z *encWr) endErr() error {
if z.bytes {
return z.wb.endErr()
}
return z.wf.endErr()
}
func (z *encWr) end() {
halt.onerror(z.endErr())
}
var _ encWriter = (*encWr)(nil)