Method ToText

logline.go:152–220

ToText converts back the LogLine to textual format and appends it to the specified buffer. If called on a default constructed LogLine (zero-value), ToText returns nil, which is an useless but syntactically valid buffer.

(buf []byte)

// If called on a default constructed LogLine (zero-value), ToText
// returns nil, which is an useless but syntactically valid buffer.
func (l *LogLine) ToText(buf []byte) []byte {
	// Fast path: if no fields have been written, we can just copy the
	// content of the original buffer and return it.
	if l.wcnt == 0 {
		blen, bcap, dlen := len(buf), cap(buf), len(l.data)
		avail := bcap - blen
		if avail < dlen {
			// Not enough capacity: create a new buffer big enough to hold the
			// previous buffer data, which we copy into, and the log line data.
			newbuf := make([]byte, blen+dlen)
			copy(newbuf, buf)
			buf = newbuf
		} else {
			// We have the capacity, just reslice to the desired length.
			buf = buf[:blen+dlen]
		}
		copy(buf[blen:], l.data)
		return buf
	}

	// Get the last setted index in the write array.
	var last int
	for i := int(LogLineNumFields) - 1; i > 0; i-- {
		if l.wmask[i] != 0 {
			last = i
			break
		}
	}

	// Get the last index in the data buffer.
	if l.data != nil {
		var lastr int
		for i := len(l.idx) - 1; i > 0; i-- {
			if l.idx[i] != 0 {
				lastr = i - 1
				break
			}
		}
		// Update last value.
		if last < lastr {
			last = lastr
		}
	}

	// Compute an estimate of the max capacity required, so only one
	// allocation will ever be performed.
	var wlen int
	for i := uint8(1); i <= l.wcnt; i++ {
		wlen += len(l.wdata[i])
	}
	wlen += int(l.wcnt) - 1 // Add 1 additional byte per separator.

	blen, bcap, dlen := len(buf), cap(buf), len(l.data)
	avail := bcap - blen
	if avail < wlen+dlen {
		newbuf := make([]byte, blen, blen+dlen+wlen)
		copy(newbuf, buf)
		buf = newbuf