Use git log name-status in get last commit (#16059)

* Improve get last commit using git log --name-status

git log --name-status -c provides information about the diff between a
commit and its parents. Using this and adjusting the algorithm to use
the first change to a path allows for a much faster generation of commit
info.

There is a subtle change in the results generated but this will cause
the results to more closely match those from elsewhere.

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lauris BH <lauris@nix.lv>
This commit is contained in:
zeripath 2021-06-20 23:00:46 +01:00 committed by GitHub
parent 8fa3bbc424
commit 23358bc55d
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
40 changed files with 2540 additions and 297 deletions

View file

@ -11,6 +11,9 @@ import (
"math"
"strconv"
"strings"
"github.com/djherbis/buffer"
"github.com/djherbis/nio/v3"
)
// WriteCloserError wraps an io.WriteCloser with an additional CloseWithError function
@ -42,7 +45,7 @@ func CatFileBatchCheck(repoPath string) (WriteCloserError, *bufio.Reader, func()
}
}()
// For simplicities sake we'll us a buffered reader to read from the cat-file --batch
// For simplicities sake we'll use a buffered reader to read from the cat-file --batch-check
batchReader := bufio.NewReader(batchStdoutReader)
return batchStdinWriter, batchReader, cancel
@ -53,7 +56,7 @@ func CatFileBatch(repoPath string) (WriteCloserError, *bufio.Reader, func()) {
// We often want to feed the commits in order into cat-file --batch, followed by their trees and sub trees as necessary.
// so let's create a batch stdin and stdout
batchStdinReader, batchStdinWriter := io.Pipe()
batchStdoutReader, batchStdoutWriter := io.Pipe()
batchStdoutReader, batchStdoutWriter := nio.Pipe(buffer.New(32 * 1024))
cancel := func() {
_ = batchStdinReader.Close()
_ = batchStdinWriter.Close()
@ -74,7 +77,7 @@ func CatFileBatch(repoPath string) (WriteCloserError, *bufio.Reader, func()) {
}()
// For simplicities sake we'll us a buffered reader to read from the cat-file --batch
batchReader := bufio.NewReader(batchStdoutReader)
batchReader := bufio.NewReaderSize(batchStdoutReader, 32*1024)
return batchStdinWriter, batchReader, cancel
}
@ -84,22 +87,31 @@ func CatFileBatch(repoPath string) (WriteCloserError, *bufio.Reader, func()) {
// <sha> SP <type> SP <size> LF
// sha is a 40byte not 20byte here
func ReadBatchLine(rd *bufio.Reader) (sha []byte, typ string, size int64, err error) {
sha, err = rd.ReadBytes(' ')
if err != nil {
return
}
sha = sha[:len(sha)-1]
typ, err = rd.ReadString('\n')
if err != nil {
return
}
if len(typ) == 1 {
typ, err = rd.ReadString('\n')
if err != nil {
return
}
}
idx := strings.IndexByte(typ, ' ')
if idx < 0 {
log("missing space typ: %s", typ)
err = ErrNotExist{ID: string(sha)}
return
}
sha = []byte(typ[:idx])
typ = typ[idx+1:]
idx := strings.Index(typ, " ")
idx = strings.IndexByte(typ, ' ')
if idx < 0 {
err = ErrNotExist{ID: string(sha)}
return
}
sizeStr := typ[idx+1 : len(typ)-1]
typ = typ[:idx]
@ -130,7 +142,7 @@ headerLoop:
}
// Discard the rest of the tag
discard := size - n
discard := size - n + 1
for discard > math.MaxInt32 {
_, err := rd.Discard(math.MaxInt32)
if err != nil {
@ -200,57 +212,6 @@ func To40ByteSHA(sha, out []byte) []byte {
return out
}
// ParseTreeLineSkipMode reads an entry from a tree in a cat-file --batch stream
// This simply skips the mode - saving a substantial amount of time and carefully avoids allocations - except where fnameBuf is too small.
// It is recommended therefore to pass in an fnameBuf large enough to avoid almost all allocations
//
// Each line is composed of:
// <mode-in-ascii-dropping-initial-zeros> SP <fname> NUL <20-byte SHA>
//
// We don't attempt to convert the 20-byte SHA to 40-byte SHA to save a lot of time
func ParseTreeLineSkipMode(rd *bufio.Reader, fnameBuf, shaBuf []byte) (fname, sha []byte, n int, err error) {
var readBytes []byte
// Skip the Mode
readBytes, err = rd.ReadSlice(' ') // NB: DOES NOT ALLOCATE SIMPLY RETURNS SLICE WITHIN READER BUFFER
if err != nil {
return
}
n += len(readBytes)
// Deal with the fname
readBytes, err = rd.ReadSlice('\x00')
copy(fnameBuf, readBytes)
if len(fnameBuf) > len(readBytes) {
fnameBuf = fnameBuf[:len(readBytes)] // cut the buf the correct size
} else {
fnameBuf = append(fnameBuf, readBytes[len(fnameBuf):]...) // extend the buf and copy in the missing bits
}
for err == bufio.ErrBufferFull { // Then we need to read more
readBytes, err = rd.ReadSlice('\x00')
fnameBuf = append(fnameBuf, readBytes...) // there is little point attempting to avoid allocations here so just extend
}
n += len(fnameBuf)
if err != nil {
return
}
fnameBuf = fnameBuf[:len(fnameBuf)-1] // Drop the terminal NUL
fname = fnameBuf // set the returnable fname to the slice
// Now deal with the 20-byte SHA
idx := 0
for idx < 20 {
read := 0
read, err = rd.Read(shaBuf[idx:20])
n += read
if err != nil {
return
}
idx += read
}
sha = shaBuf
return
}
// ParseTreeLine reads an entry from a tree in a cat-file --batch stream
// This carefully avoids allocations - except where fnameBuf is too small.
// It is recommended therefore to pass in an fnameBuf large enough to avoid almost all allocations
@ -262,23 +223,31 @@ func ParseTreeLineSkipMode(rd *bufio.Reader, fnameBuf, shaBuf []byte) (fname, sh
func ParseTreeLine(rd *bufio.Reader, modeBuf, fnameBuf, shaBuf []byte) (mode, fname, sha []byte, n int, err error) {
var readBytes []byte
// Read the Mode
readBytes, err = rd.ReadSlice(' ')
// Read the Mode & fname
readBytes, err = rd.ReadSlice('\x00')
if err != nil {
return
}
n += len(readBytes)
copy(modeBuf, readBytes)
if len(modeBuf) > len(readBytes) {
modeBuf = modeBuf[:len(readBytes)]
} else {
modeBuf = append(modeBuf, readBytes[len(modeBuf):]...)
idx := bytes.IndexByte(readBytes, ' ')
if idx < 0 {
log("missing space in readBytes ParseTreeLine: %s", readBytes)
err = &ErrNotExist{}
return
}
mode = modeBuf[:len(modeBuf)-1] // Drop the SP
n += idx + 1
copy(modeBuf, readBytes[:idx])
if len(modeBuf) >= idx {
modeBuf = modeBuf[:idx]
} else {
modeBuf = append(modeBuf, readBytes[len(modeBuf):idx]...)
}
mode = modeBuf
readBytes = readBytes[idx+1:]
// Deal with the fname
readBytes, err = rd.ReadSlice('\x00')
copy(fnameBuf, readBytes)
if len(fnameBuf) > len(readBytes) {
fnameBuf = fnameBuf[:len(readBytes)]
@ -297,7 +266,7 @@ func ParseTreeLine(rd *bufio.Reader, modeBuf, fnameBuf, shaBuf []byte) (mode, fn
fname = fnameBuf
// Deal with the 20-byte SHA
idx := 0
idx = 0
for idx < 20 {
read := 0
read, err = rd.Read(shaBuf[idx:20])