godoc: support for complete index serialization

- now fulltext index information is saved/restored
- minor updates to appinit.go

R=rsc
CC=golang-dev
https://golang.org/cl/5024043

src/cmd/godoc/appinit.go

@@ -4,8 +4,9 @@
 
 // To run godoc under app engine, substitute main.go with
 // this file (appinit.go), provide a .zip file containing
-// the file system to serve, and adjust the configuration
-// parameters in appconfig.go accordingly.
+// the file system to serve, the index file (or files)
+// containing the pre-computed search index and adjust
+// the configuration parameters in appconfig.go accordingly.
 //
 // The current app engine SDK may be based on an older Go
 // release version. To correct for version skew, copy newer
@@ -17,7 +18,7 @@
 //
 // The directory structure should look as follows:
 //
-// godoc			// directory containing the app engine app
+// godoc-app			// directory containing the app engine app
 //      alt			// alternative packages directory to
 //				//	correct for version skew
 //		strings		// never version of the strings package
@@ -32,9 +33,8 @@
 //
 // To run app the engine emulator locally:
 //
-//	dev_appserver.py -a 0 godoc
+//	dev_appserver.py -a 0 godoc-app
 //
-// godoc is the top-level "goroot" directory.
 // The godoc home page is served at: <hostname>:8080 and localhost:8080.
 
 package main
@@ -63,7 +63,7 @@ func init() {
 	*goroot = path.Join("/", zipGoroot) // fsHttp paths are relative to '/'
 	*indexEnabled = true
 	*indexFiles = indexFilenames
-	*maxResults = 0      // save space for now
+	*maxResults = 100    // reduce latency by limiting the number of fulltext search results
 	*indexThrottle = 0.3 // in case *indexFiles is empty (and thus the indexer is run)
 
 	// read .zip file and set up file systems
@@ -72,6 +72,7 @@ func init() {
 	if err != nil {
 		log.Fatalf("%s: %s\n", zipfile, err)
 	}
+	// rc is never closed (app running forever)
 	fs = NewZipFS(rc)
 	fsHttp = NewHttpZipFS(rc, *goroot)
 

src/cmd/godoc/index.go

@@ -833,7 +833,8 @@ func NewIndex(dirnames <-chan string, fulltextIndex bool, throttle float64) *Ind
 	return &Index{x.fset, suffixes, words, alts, x.snippets, x.stats}
 }
 
-type FileIndex struct {
+type fileIndex struct {
+	Sources  []byte
 	Words    map[string]*LookupResult
 	Alts     map[string]*AltWords
 	Snippets []*Snippet
@@ -841,23 +842,38 @@ type FileIndex struct {
 
 // Write writes the index x to w.
 func (x *Index) Write(w io.Writer) os.Error {
+	var sources []byte
 	if x.suffixes != nil {
-		panic("no support for writing full text index yet")
+		// fulltext index present
+		sources = x.suffixes.Bytes()
 	}
-	fx := FileIndex{
+	fx := fileIndex{
+		sources, // indicates if fulltext index is present or not
 		x.words,
 		x.alts,
 		x.snippets,
 	}
-	return gob.NewEncoder(w).Encode(fx)
+	err := gob.NewEncoder(w).Encode(fx)
+	if err == nil && sources != nil {
+		err = x.fset.Write(w)
+	}
+	return err
 }
 
 // Read reads the index from r into x; x must not be nil.
 func (x *Index) Read(r io.Reader) os.Error {
-	var fx FileIndex
+	var fx fileIndex
 	if err := gob.NewDecoder(r).Decode(&fx); err != nil {
 		return err
 	}
+	if fx.Sources != nil {
+		// fulltext index is present
+		x.fset = token.NewFileSet()
+		if err := x.fset.Read(r); err != nil {
+			return err
+		}
+		x.suffixes = suffixarray.New(fx.Sources)
+	}
 	x.words = fx.Words
 	x.alts = fx.Alts
 	x.snippets = fx.Snippets

src/cmd/godoc/main.go

@@ -257,11 +257,6 @@ func main() {
 	readTemplates()
 	initHandlers()
 
-	if (*indexEnabled || *writeIndex) && *indexFiles != "" && *maxResults > 0 {
-		log.Println("warning: no support for full-text index yet (setting -maxresults to 0)")
-		*maxResults = 0
-	}
-
 	if *writeIndex {
 		// Write search index and exit.
 		if *indexFiles == "" {