add replacement strings support, reuse variables with loops (less allocs)

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

core/conn.go

@@ -67,9 +67,15 @@ func (c *conn) ReadLine() ([]byte, Error) {
 	// return slice
 	b := make([]byte, 0)
 
+	// Declare variables
+	var line []byte
+	var isPrefix bool
+	var err error
+
+	// Read!
 	for len(b) < connReadMax {
 		// read the line
-		line, isPrefix, err := c.buf.ReadLine()
+		line, isPrefix, err = c.buf.ReadLine()
 		if err != nil {
 			return nil, WrapError(ConnReadErr, err)
 		}

core/filesystem.go

@@ -65,7 +65,7 @@ func (fs *FileSystemObject) checkCacheFreshness() {
 		// Check file still exists on disk
 		stat, err := os.Stat(path)
 		if err != nil {
-			SystemLog.Error("Failed to stat file in cache: %s\n", path)
+			SystemLog.Error(cacheFileStatErrStr, path)
 			fs.cache.Remove(path)
 			return
 		}
@@ -107,9 +107,13 @@ func (fs *FileSystemObject) ReadFile(fd *os.File) ([]byte, Error) {
 	// Read buffer
 	buf := make([]byte, fileReadBufSize)
 
+	// Declare variables
+	var count int
+	var err error
+
 	// Read through file until null bytes / error
 	for {
-		count, err := fd.Read(buf)
+		count, err = fd.Read(buf)
 		if err != nil {
 			if err == io.EOF {
 				break
@@ -132,17 +136,24 @@ func (fs *FileSystemObject) ScanFile(fd *os.File, iterator func(string) bool) Er
 	// Buffered reader
 	rdr := bufio.NewReaderSize(fd, fileReadBufSize)
 
+	// Declare variables
+	var b, line []byte
+	var err error
+	var isPrefix, done bool
+
 	// Iterate through file!
 	for {
 		// Line buffer
-		b := make([]byte, 0)
+		b = make([]byte, 0)
 
 		// Read until line-end, or file end!
+		done = false
 		for {
 			// Read a line
-			line, isPrefix, err := rdr.ReadLine()
+			line, isPrefix, err = rdr.ReadLine()
 			if err != nil {
 				if err == io.EOF {
+					done = true
 					break
 				}
 				return WrapError(FileReadErr, err)
@@ -158,9 +169,12 @@ func (fs *FileSystemObject) ScanFile(fd *os.File, iterator func(string) bool) Er
 		}
 
 		// Run scan iterator on this line, break-out if requested
-		if !iterator(string(b)) {
+		if !iterator(string(b)) || done {
 			break
 		}
+
+		// Empty the slice!
+		b = nil
 	}
 
 	return nil
@@ -176,10 +190,13 @@ func (fs *FileSystemObject) ScanDirectory(fd *os.File, p *Path, iterator func(os
 	// Sort by name
 	sort.Sort(byName(dirList))
 
+	// Declare variables
+	var fp *Path
+
 	// Walk through the directory list using supplied iterator function
 	for _, info := range dirList {
 		// Make new Path object
-		fp := p.JoinPath(info.Name())
+		fp = p.JoinPath(info.Name())
 
 		// Skip restricted files
 		if IsRestrictedPath(fp) || WithinCGIDir(fp) {
@@ -337,7 +354,7 @@ func (fs *FileSystemObject) FetchFile(client *Client, fd *os.File, stat os.FileI
 		}
 	}
 
-	// Defer file unlock, write to client
+	// Defer file read unlock, write to client
 	defer f.RUnlock()
 	return f.WriteToClient(client, p)
 }

core/string_constants.go

@@ -89,6 +89,7 @@ const (
 	listeningOnStr       = "Listening on %s://%s:%s (%s:%s)"
 
 	cacheMonitorStartStr = "Starting cache monitor with freq: %s"
+	cacheFileStatErrStr  = "Failed to stat file in cache: %s"
 
 	pathRestrictionsEnabledStr      = "Path restrictions enabled"
 	pathRestrictionsDisabledStr     = "Path restrictions disabled"

gopher/filecontents.go

@@ -12,8 +12,12 @@ type gophermapContents struct {
 
 // WriteToClient renders each cached section of the gophermap, and writes them to the client
 func (gc *gophermapContents) WriteToClient(client *core.Client, path *core.Path) core.Error {
+	// Declare variables
+	var err core.Error
+
+	// Render + write the sections!
 	for _, section := range gc.sections {
-		err := section.RenderAndWrite(client)
+		err = section.RenderAndWrite(client)
 		if err != nil {
 			return err
 		}

gopher/format.go

@@ -43,6 +43,22 @@ func formatHostPort(host, port string) string {
 	return host + "\t" + port
 }
 
+// replacePlacementStrs replaces any placement strings found in the line (e.g $hostname, $port)
+func replacePlacementStrs(line string) string {
+	split := strings.Split(line, "\t")
+
+	// Either invalid line, or information line without host + port
+	if len(split) != 4 {
+		return line
+	}
+
+	// Return recombined (and replaced! string)
+	return split[0] + "\t" +
+		split[1] + "\t" +
+		strings.Replace(split[2], "$hostname", core.Hostname, 1) + "\t" +
+		strings.Replace(split[3], "$port", core.FwdPort, 1)
+}
+
 // buildLine builds a gopher line string
 func buildLine(t ItemType, name, selector, host, port string) []byte {
 	return []byte(string(t) + formatName(name) + formatSelector(selector) + formatHostPort(host, port) + "\r\n")

gopher/gophermap.go

@@ -25,11 +25,11 @@ func readGophermap(fd *os.File, p *core.Path) ([]gophermapSection, core.Error) {
 		p.Relative(): true,
 	}
 
-	// Error setting within nested function below
+	// Declare variables
 	var returnErr core.Error
+	titleAlready := false
 
 	// Perform scan of gophermap FD
-	titleAlready := false
 	scanErr := core.FileSystem.ScanFile(
 		fd,
 		func(line string) bool {
@@ -120,8 +120,8 @@ func readGophermap(fd *os.File, p *core.Path) ([]gophermapSection, core.Error) {
 				return false
 
 			default:
-				// Default is appending to sections slice as TextSection
-				sections = append(sections, &TextSection{[]byte(line + "\r\n")})
+				// Default is appending line with replaced strings to sections slice as TextSection
+				sections = append(sections, &TextSection{[]byte(replacePlacementStrs(line) + "\r\n")})
 				return true
 			}
 		},

gopher/server.go

@@ -50,6 +50,7 @@ func serve(client *core.Client) {
 			if err == nil {
 				stat, osErr := fd2.Stat()
 				if osErr == nil {
+					core.SystemLog.Info("Returning fetched gophermap")
 					return fs.FetchFile(client, fd2, stat, gophermap, newFileContents)
 				}