switch to std http implementation instead of fasthttp (#106)

close #100
close #109
close #113
close #28
close #63

Reviewed-on: https://codeberg.org/Codeberg/pages-server/pulls/106

server/gitea/cache.go

@@ -1,12 +1,116 @@
 package gitea
 
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/rs/zerolog/log"
+
+	"codeberg.org/codeberg/pages/server/cache"
+)
+
+const (
+	// defaultBranchCacheTimeout specifies the timeout for the default branch cache. It can be quite long.
+	defaultBranchCacheTimeout = 15 * time.Minute
+
+	// branchExistenceCacheTimeout specifies the timeout for the branch timestamp & existence cache. It should be shorter
+	// than fileCacheTimeout, as that gets invalidated if the branch timestamp has changed. That way, repo changes will be
+	// picked up faster, while still allowing the content to be cached longer if nothing changes.
+	branchExistenceCacheTimeout = 5 * time.Minute
+
+	// fileCacheTimeout specifies the timeout for the file content cache - you might want to make this quite long, depending
+	// on your available memory.
+	// TODO: move as option into cache interface
+	fileCacheTimeout = 5 * time.Minute
+
+	// fileCacheSizeLimit limits the maximum file size that will be cached, and is set to 1 MB by default.
+	fileCacheSizeLimit = int64(1000 * 1000)
+)
+
 type FileResponse struct {
-	Exists   bool
-	ETag     []byte
-	MimeType string
-	Body     []byte
+	Exists    bool
+	IsSymlink bool
+	ETag      string
+	MimeType  string
+	Body      []byte
 }
 
 func (f FileResponse) IsEmpty() bool {
 	return len(f.Body) != 0
 }
+
+func (f FileResponse) createHttpResponse(cacheKey string) (http.Header, int) {
+	header := make(http.Header)
+	var statusCode int
+
+	if f.Exists {
+		statusCode = http.StatusOK
+	} else {
+		statusCode = http.StatusNotFound
+	}
+
+	if f.IsSymlink {
+		header.Set(giteaObjectTypeHeader, objTypeSymlink)
+	}
+	header.Set(ETagHeader, f.ETag)
+	header.Set(ContentTypeHeader, f.MimeType)
+	header.Set(ContentLengthHeader, fmt.Sprintf("%d", len(f.Body)))
+	header.Set(PagesCacheIndicatorHeader, "true")
+
+	log.Trace().Msgf("fileCache for %q used", cacheKey)
+	return header, statusCode
+}
+
+type BranchTimestamp struct {
+	Branch    string
+	Timestamp time.Time
+	notFound  bool
+}
+
+type writeCacheReader struct {
+	originalReader io.ReadCloser
+	buffer         *bytes.Buffer
+	rileResponse   *FileResponse
+	cacheKey       string
+	cache          cache.SetGetKey
+	hasError       bool
+}
+
+func (t *writeCacheReader) Read(p []byte) (n int, err error) {
+	n, err = t.originalReader.Read(p)
+	if err != nil {
+		log.Trace().Err(err).Msgf("[cache] original reader for %q has returned an error", t.cacheKey)
+		t.hasError = true
+	} else if n > 0 {
+		_, _ = t.buffer.Write(p[:n])
+	}
+	return
+}
+
+func (t *writeCacheReader) Close() error {
+	if !t.hasError {
+		fc := *t.rileResponse
+		fc.Body = t.buffer.Bytes()
+		_ = t.cache.Set(t.cacheKey, fc, fileCacheTimeout)
+	}
+	log.Trace().Msgf("cacheReader for %q saved=%t closed", t.cacheKey, !t.hasError)
+	return t.originalReader.Close()
+}
+
+func (f FileResponse) CreateCacheReader(r io.ReadCloser, cache cache.SetGetKey, cacheKey string) io.ReadCloser {
+	if r == nil || cache == nil || cacheKey == "" {
+		log.Error().Msg("could not create CacheReader")
+		return nil
+	}
+
+	return &writeCacheReader{
+		originalReader: r,
+		buffer:         bytes.NewBuffer(make([]byte, 0)),
+		rileResponse:   &f,
+		cache:          cache,
+		cacheKey:       cacheKey,
+	}
+}