Files
byre/internal/git/changes.go
T

157 lines
3.5 KiB
Go

package git
import (
"fmt"
"os"
"strconv"
"strings"
"g.fc.run/ai/byre/internal/api"
)
var statuses = map[byte]api.FileChangeStatus{
'A': api.Added,
'M': api.Modified,
'D': api.Deleted,
'R': api.Renamed,
'T': api.TypeChanged,
}
func Changes(dir, defaultBranch, since string) (api.TaskChanges, error) {
tree, err := Snapshot(dir)
if err != nil {
return api.TaskChanges{}, err
}
return Compare(dir, defaultBranch, "HEAD", tree, since)
}
func Compare(dir, defaultBranch, head, tree, since string) (api.TaskChanges, error) {
base := since
if base == "" {
mb, err := run(dir, "merge-base", head, defaultBranch)
if err != nil {
return api.TaskChanges{}, err
}
base = mb
}
files, err := stats(dir, base, tree)
if err != nil {
return api.TaskChanges{}, err
}
return api.TaskChanges{Base: base, Tree: tree, Files: files}, nil
}
func Snapshot(dir string) (string, error) {
index, err := run(dir, "rev-parse", "--path-format=absolute", "--git-path", "index")
if err != nil {
return "", err
}
info, err := os.Stat(index)
if err != nil {
return "", err
}
data, err := os.ReadFile(index)
if err != nil {
return "", err
}
tmp, err := os.CreateTemp("", "byre-index-*")
if err != nil {
return "", err
}
defer os.Remove(tmp.Name())
_, err = tmp.Write(data)
if err != nil {
tmp.Close()
return "", err
}
err = tmp.Close()
if err != nil {
return "", err
}
// git trusts cached stat data for entries older than the index file; a fresh mtime would hide same-size edits.
err = os.Chtimes(tmp.Name(), info.ModTime(), info.ModTime())
if err != nil {
return "", err
}
env := []string{"GIT_INDEX_FILE=" + tmp.Name()}
_, err = runEnv(dir, env, "add", "--all")
if err != nil {
return "", err
}
return runEnv(dir, env, "write-tree")
}
func FileDiff(dir, base, tree, path, oldPath string) (string, error) {
args := []string{"diff", "--find-renames", "--no-ext-diff", "--no-color", base, tree, "--", path}
if oldPath != "" {
args = append(args, oldPath)
}
return run(dir, args...)
}
func stats(dir, base, tree string) ([]api.FileChange, error) {
nameStatus, err := run(dir, "diff", "--find-renames", "--name-status", "-z", base, tree)
if err != nil {
return nil, err
}
numstat, err := run(dir, "diff", "--find-renames", "--numstat", "-z", base, tree)
if err != nil {
return nil, err
}
counts := map[string]api.FileChange{}
tokens := strings.Split(numstat, "\x00")
for i := 0; i < len(tokens); i++ {
fields := strings.SplitN(tokens[i], "\t", 3)
if len(fields) != 3 {
continue
}
path := fields[2]
if path == "" && i+2 < len(tokens) {
path = tokens[i+2]
i += 2
}
c := api.FileChange{Binary: fields[0] == "-"}
c.Additions, _ = strconv.Atoi(fields[0])
c.Deletions, _ = strconv.Atoi(fields[1])
counts[path] = c
}
files := []api.FileChange{}
tokens = strings.Split(nameStatus, "\x00")
for i := 0; i < len(tokens); i++ {
code := tokens[i]
if code == "" {
continue
}
status, ok := statuses[code[0]]
if !ok {
return nil, fmt.Errorf("unknown diff status %q", code)
}
f := api.FileChange{Status: status}
if status == api.Renamed {
if i+2 >= len(tokens) {
return nil, fmt.Errorf("truncated rename in name-status output")
}
old := tokens[i+1]
f.OldPath = &old
f.Path = tokens[i+2]
i += 2
} else {
if i+1 >= len(tokens) {
return nil, fmt.Errorf("truncated name-status output")
}
f.Path = tokens[i+1]
i++
}
c := counts[f.Path]
f.Additions, f.Deletions, f.Binary = c.Additions, c.Deletions, c.Binary
files = append(files, f)
}
return files, nil
}