| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // This file contains the infrastructure to create an |
| // identifier and full-text index for a set of Go files. |
| // |
| // Algorithm for identifier index: |
| // - traverse all .go files of the file tree specified by root |
| // - for each word (identifier) encountered, collect all occurrences (spots) |
| // into a list; this produces a list of spots for each word |
| // - reduce the lists: from a list of spots to a list of FileRuns, |
| // and from a list of FileRuns into a list of PakRuns |
| // - make a HitList from the PakRuns |
| // |
| // Details: |
| // - keep two lists per word: one containing package-level declarations |
| // that have snippets, and one containing all other spots |
| // - keep the snippets in a separate table indexed by snippet index |
| // and store the snippet index in place of the line number in a SpotInfo |
| // (the line number for spots with snippets is stored in the snippet) |
| // - at the end, create lists of alternative spellings for a given |
| // word |
| // |
| // Algorithm for full text index: |
| // - concatenate all source code in a byte buffer (in memory) |
| // - add the files to a file set in lockstep as they are added to the byte |
| // buffer such that a byte buffer offset corresponds to the Pos value for |
| // that file location |
| // - create a suffix array from the concatenated sources |
| // |
| // String lookup in full text index: |
| // - use the suffix array to lookup a string's offsets - the offsets |
| // correspond to the Pos values relative to the file set |
| // - translate the Pos values back into file and line information and |
| // sort the result |
| |
| package main |
| |
| import ( |
| "bytes" |
| "container/vector" |
| "go/ast" |
| "go/parser" |
| "go/token" |
| "go/scanner" |
| "index/suffixarray" |
| "io/ioutil" |
| "os" |
| "path" |
| "regexp" |
| "sort" |
| "strings" |
| ) |
| |
| |
| // ---------------------------------------------------------------------------- |
| // RunList |
| |
| // A RunList is a vector of entries that can be sorted according to some |
| // criteria. A RunList may be compressed by grouping "runs" of entries |
| // which are equal (according to the sort critera) into a new RunList of |
| // runs. For instance, a RunList containing pairs (x, y) may be compressed |
| // into a RunList containing pair runs (x, {y}) where each run consists of |
| // a list of y's with the same x. |
| type RunList struct { |
| vector.Vector |
| less func(x, y interface{}) bool |
| } |
| |
| func (h *RunList) Less(i, j int) bool { return h.less(h.At(i), h.At(j)) } |
| |
| |
| func (h *RunList) sort(less func(x, y interface{}) bool) { |
| h.less = less |
| sort.Sort(h) |
| } |
| |
| |
| // Compress entries which are the same according to a sort criteria |
| // (specified by less) into "runs". |
| func (h *RunList) reduce(less func(x, y interface{}) bool, newRun func(h *RunList, i, j int) interface{}) *RunList { |
| // create runs of entries with equal values |
| h.sort(less) |
| |
| // for each run, make a new run object and collect them in a new RunList |
| var hh RunList |
| i := 0 |
| for j := 0; j < h.Len(); j++ { |
| if less(h.At(i), h.At(j)) { |
| hh.Push(newRun(h, i, j)) |
| i = j // start a new run |
| } |
| } |
| // add final run, if any |
| if i < h.Len() { |
| hh.Push(newRun(h, i, h.Len())) |
| } |
| |
| return &hh |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // SpotInfo |
| |
| // A SpotInfo value describes a particular identifier spot in a given file; |
| // It encodes three values: the SpotKind (declaration or use), a line or |
| // snippet index "lori", and whether it's a line or index. |
| // |
| // The following encoding is used: |
| // |
| // bits 32 4 1 0 |
| // value [lori|kind|isIndex] |
| // |
| type SpotInfo uint32 |
| |
| // SpotKind describes whether an identifier is declared (and what kind of |
| // declaration) or used. |
| type SpotKind uint32 |
| |
| const ( |
| PackageClause SpotKind = iota |
| ImportDecl |
| ConstDecl |
| TypeDecl |
| VarDecl |
| FuncDecl |
| MethodDecl |
| Use |
| nKinds |
| ) |
| |
| |
| func init() { |
| // sanity check: if nKinds is too large, the SpotInfo |
| // accessor functions may need to be updated |
| if nKinds > 8 { |
| panic("nKinds > 8") |
| } |
| } |
| |
| |
| // makeSpotInfo makes a SpotInfo. |
| func makeSpotInfo(kind SpotKind, lori int, isIndex bool) SpotInfo { |
| // encode lori: bits [4..32) |
| x := SpotInfo(lori) << 4 |
| if int(x>>4) != lori { |
| // lori value doesn't fit - since snippet indices are |
| // most certainly always smaller then 1<<28, this can |
| // only happen for line numbers; give it no line number (= 0) |
| x = 0 |
| } |
| // encode kind: bits [1..4) |
| x |= SpotInfo(kind) << 1 |
| // encode isIndex: bit 0 |
| if isIndex { |
| x |= 1 |
| } |
| return x |
| } |
| |
| |
| func (x SpotInfo) Kind() SpotKind { return SpotKind(x >> 1 & 7) } |
| func (x SpotInfo) Lori() int { return int(x >> 4) } |
| func (x SpotInfo) IsIndex() bool { return x&1 != 0 } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // KindRun |
| |
| // Debugging support. Disable to see multiple entries per line. |
| const removeDuplicates = true |
| |
| // A KindRun is a run of SpotInfos of the same kind in a given file. |
| type KindRun struct { |
| Kind SpotKind |
| Infos []SpotInfo |
| } |
| |
| |
| // KindRuns are sorted by line number or index. Since the isIndex bit |
| // is always the same for all infos in one list we can compare lori's. |
| func (f *KindRun) Len() int { return len(f.Infos) } |
| func (f *KindRun) Less(i, j int) bool { return f.Infos[i].Lori() < f.Infos[j].Lori() } |
| func (f *KindRun) Swap(i, j int) { f.Infos[i], f.Infos[j] = f.Infos[j], f.Infos[i] } |
| |
| |
| // FileRun contents are sorted by Kind for the reduction into KindRuns. |
| func lessKind(x, y interface{}) bool { return x.(SpotInfo).Kind() < y.(SpotInfo).Kind() } |
| |
| |
| // newKindRun allocates a new KindRun from the SpotInfo run [i, j) in h. |
| func newKindRun(h *RunList, i, j int) interface{} { |
| kind := h.At(i).(SpotInfo).Kind() |
| infos := make([]SpotInfo, j-i) |
| k := 0 |
| for ; i < j; i++ { |
| infos[k] = h.At(i).(SpotInfo) |
| k++ |
| } |
| run := &KindRun{kind, infos} |
| |
| // Spots were sorted by file and kind to create this run. |
| // Within this run, sort them by line number or index. |
| sort.Sort(run) |
| |
| if removeDuplicates { |
| // Since both the lori and kind field must be |
| // same for duplicates, and since the isIndex |
| // bit is always the same for all infos in one |
| // list we can simply compare the entire info. |
| k := 0 |
| var prev SpotInfo |
| for i, x := range infos { |
| if x != prev || i == 0 { |
| infos[k] = x |
| k++ |
| prev = x |
| } |
| } |
| run.Infos = infos[0:k] |
| } |
| |
| return run |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // FileRun |
| |
| // A Pak describes a Go package. |
| type Pak struct { |
| Path string // path of directory containing the package |
| Name string // package name as declared by package clause |
| } |
| |
| // Paks are sorted by name (primary key) and by import path (secondary key). |
| func (p *Pak) less(q *Pak) bool { |
| return p.Name < q.Name || p.Name == q.Name && p.Path < q.Path |
| } |
| |
| |
| // A File describes a Go file. |
| type File struct { |
| Path string // complete file name |
| Pak Pak // the package to which the file belongs |
| } |
| |
| |
| // A Spot describes a single occurrence of a word. |
| type Spot struct { |
| File *File |
| Info SpotInfo |
| } |
| |
| |
| // A FileRun is a list of KindRuns belonging to the same file. |
| type FileRun struct { |
| File *File |
| Groups []*KindRun |
| } |
| |
| |
| // Spots are sorted by path for the reduction into FileRuns. |
| func lessSpot(x, y interface{}) bool { return x.(Spot).File.Path < y.(Spot).File.Path } |
| |
| |
| // newFileRun allocates a new FileRun from the Spot run [i, j) in h. |
| func newFileRun(h0 *RunList, i, j int) interface{} { |
| file := h0.At(i).(Spot).File |
| |
| // reduce the list of Spots into a list of KindRuns |
| var h1 RunList |
| h1.Vector.Resize(j-i, 0) |
| k := 0 |
| for ; i < j; i++ { |
| h1.Set(k, h0.At(i).(Spot).Info) |
| k++ |
| } |
| h2 := h1.reduce(lessKind, newKindRun) |
| |
| // create the FileRun |
| groups := make([]*KindRun, h2.Len()) |
| for i := 0; i < h2.Len(); i++ { |
| groups[i] = h2.At(i).(*KindRun) |
| } |
| return &FileRun{file, groups} |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // PakRun |
| |
| // A PakRun describes a run of *FileRuns of a package. |
| type PakRun struct { |
| Pak Pak |
| Files []*FileRun |
| } |
| |
| // Sorting support for files within a PakRun. |
| func (p *PakRun) Len() int { return len(p.Files) } |
| func (p *PakRun) Less(i, j int) bool { return p.Files[i].File.Path < p.Files[j].File.Path } |
| func (p *PakRun) Swap(i, j int) { p.Files[i], p.Files[j] = p.Files[j], p.Files[i] } |
| |
| |
| // FileRuns are sorted by package for the reduction into PakRuns. |
| func lessFileRun(x, y interface{}) bool { |
| return x.(*FileRun).File.Pak.less(&y.(*FileRun).File.Pak) |
| } |
| |
| |
| // newPakRun allocates a new PakRun from the *FileRun run [i, j) in h. |
| func newPakRun(h *RunList, i, j int) interface{} { |
| pak := h.At(i).(*FileRun).File.Pak |
| files := make([]*FileRun, j-i) |
| k := 0 |
| for ; i < j; i++ { |
| files[k] = h.At(i).(*FileRun) |
| k++ |
| } |
| run := &PakRun{pak, files} |
| sort.Sort(run) // files were sorted by package; sort them by file now |
| return run |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // HitList |
| |
| // A HitList describes a list of PakRuns. |
| type HitList []*PakRun |
| |
| |
| // PakRuns are sorted by package. |
| func lessPakRun(x, y interface{}) bool { return x.(*PakRun).Pak.less(&y.(*PakRun).Pak) } |
| |
| |
| func reduce(h0 *RunList) HitList { |
| // reduce a list of Spots into a list of FileRuns |
| h1 := h0.reduce(lessSpot, newFileRun) |
| // reduce a list of FileRuns into a list of PakRuns |
| h2 := h1.reduce(lessFileRun, newPakRun) |
| // sort the list of PakRuns by package |
| h2.sort(lessPakRun) |
| // create a HitList |
| h := make(HitList, h2.Len()) |
| for i := 0; i < h2.Len(); i++ { |
| h[i] = h2.At(i).(*PakRun) |
| } |
| return h |
| } |
| |
| |
| func (h HitList) filter(pakname string) HitList { |
| // determine number of matching packages (most of the time just one) |
| n := 0 |
| for _, p := range h { |
| if p.Pak.Name == pakname { |
| n++ |
| } |
| } |
| // create filtered HitList |
| hh := make(HitList, n) |
| i := 0 |
| for _, p := range h { |
| if p.Pak.Name == pakname { |
| hh[i] = p |
| i++ |
| } |
| } |
| return hh |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // AltWords |
| |
| type wordPair struct { |
| canon string // canonical word spelling (all lowercase) |
| alt string // alternative spelling |
| } |
| |
| |
| // An AltWords describes a list of alternative spellings for a |
| // canonical (all lowercase) spelling of a word. |
| type AltWords struct { |
| Canon string // canonical word spelling (all lowercase) |
| Alts []string // alternative spelling for the same word |
| } |
| |
| |
| // wordPairs are sorted by their canonical spelling. |
| func lessWordPair(x, y interface{}) bool { return x.(*wordPair).canon < y.(*wordPair).canon } |
| |
| |
| // newAltWords allocates a new AltWords from the *wordPair run [i, j) in h. |
| func newAltWords(h *RunList, i, j int) interface{} { |
| canon := h.At(i).(*wordPair).canon |
| alts := make([]string, j-i) |
| k := 0 |
| for ; i < j; i++ { |
| alts[k] = h.At(i).(*wordPair).alt |
| k++ |
| } |
| return &AltWords{canon, alts} |
| } |
| |
| |
| func (a *AltWords) filter(s string) *AltWords { |
| if len(a.Alts) == 1 && a.Alts[0] == s { |
| // there are no different alternatives |
| return nil |
| } |
| |
| // make a new AltWords with the current spelling removed |
| alts := make([]string, len(a.Alts)) |
| i := 0 |
| for _, w := range a.Alts { |
| if w != s { |
| alts[i] = w |
| i++ |
| } |
| } |
| return &AltWords{a.Canon, alts[0:i]} |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Indexer |
| |
| // Adjust these flags as seems best. |
| const includeMainPackages = true |
| const includeTestFiles = true |
| |
| |
| type IndexResult struct { |
| Decls RunList // package-level declarations (with snippets) |
| Others RunList // all other occurrences |
| } |
| |
| |
| // Statistics provides statistics information for an index. |
| type Statistics struct { |
| Bytes int // total size of indexed source files |
| Files int // number of indexed source files |
| Lines int // number of lines (all files) |
| Words int // number of different identifiers |
| Spots int // number of identifier occurrences |
| } |
| |
| |
| // An Indexer maintains the data structures and provides the machinery |
| // for indexing .go files under a file tree. It implements the path.Visitor |
| // interface for walking file trees, and the ast.Visitor interface for |
| // walking Go ASTs. |
| type Indexer struct { |
| fset *token.FileSet // file set for all indexed files |
| sources bytes.Buffer // concatenated sources |
| words map[string]*IndexResult // RunLists of Spots |
| snippets vector.Vector // vector of *Snippets, indexed by snippet indices |
| current *token.File // last file added to file set |
| file *File // AST for current file |
| decl ast.Decl // AST for current decl |
| stats Statistics |
| } |
| |
| |
| func (x *Indexer) addSnippet(s *Snippet) int { |
| index := x.snippets.Len() |
| x.snippets.Push(s) |
| return index |
| } |
| |
| |
| func (x *Indexer) visitComment(c *ast.CommentGroup) { |
| if c != nil { |
| ast.Walk(x, c) |
| } |
| } |
| |
| |
| func (x *Indexer) visitIdent(kind SpotKind, id *ast.Ident) { |
| if id != nil { |
| lists, found := x.words[id.Name] |
| if !found { |
| lists = new(IndexResult) |
| x.words[id.Name] = lists |
| } |
| |
| if kind == Use || x.decl == nil { |
| // not a declaration or no snippet required |
| info := makeSpotInfo(kind, x.current.Line(id.Pos()), false) |
| lists.Others.Push(Spot{x.file, info}) |
| } else { |
| // a declaration with snippet |
| index := x.addSnippet(NewSnippet(x.fset, x.decl, id)) |
| info := makeSpotInfo(kind, index, true) |
| lists.Decls.Push(Spot{x.file, info}) |
| } |
| |
| x.stats.Spots++ |
| } |
| } |
| |
| |
| func (x *Indexer) visitSpec(spec ast.Spec, isVarDecl bool) { |
| switch n := spec.(type) { |
| case *ast.ImportSpec: |
| x.visitComment(n.Doc) |
| x.visitIdent(ImportDecl, n.Name) |
| ast.Walk(x, n.Path) |
| x.visitComment(n.Comment) |
| |
| case *ast.ValueSpec: |
| x.visitComment(n.Doc) |
| kind := ConstDecl |
| if isVarDecl { |
| kind = VarDecl |
| } |
| for _, n := range n.Names { |
| x.visitIdent(kind, n) |
| } |
| ast.Walk(x, n.Type) |
| for _, v := range n.Values { |
| ast.Walk(x, v) |
| } |
| x.visitComment(n.Comment) |
| |
| case *ast.TypeSpec: |
| x.visitComment(n.Doc) |
| x.visitIdent(TypeDecl, n.Name) |
| ast.Walk(x, n.Type) |
| x.visitComment(n.Comment) |
| } |
| } |
| |
| |
| func (x *Indexer) Visit(node ast.Node) ast.Visitor { |
| // TODO(gri): methods in interface types are categorized as VarDecl |
| switch n := node.(type) { |
| case nil: |
| return nil |
| |
| case *ast.Ident: |
| x.visitIdent(Use, n) |
| |
| case *ast.Field: |
| x.decl = nil // no snippets for fields |
| x.visitComment(n.Doc) |
| for _, m := range n.Names { |
| x.visitIdent(VarDecl, m) |
| } |
| ast.Walk(x, n.Type) |
| ast.Walk(x, n.Tag) |
| x.visitComment(n.Comment) |
| |
| case *ast.DeclStmt: |
| if decl, ok := n.Decl.(*ast.GenDecl); ok { |
| // local declarations can only be *ast.GenDecls |
| x.decl = nil // no snippets for local declarations |
| x.visitComment(decl.Doc) |
| for _, s := range decl.Specs { |
| x.visitSpec(s, decl.Tok == token.VAR) |
| } |
| } else { |
| // handle error case gracefully |
| ast.Walk(x, n.Decl) |
| } |
| |
| case *ast.GenDecl: |
| x.decl = n |
| x.visitComment(n.Doc) |
| for _, s := range n.Specs { |
| x.visitSpec(s, n.Tok == token.VAR) |
| } |
| |
| case *ast.FuncDecl: |
| x.visitComment(n.Doc) |
| kind := FuncDecl |
| if n.Recv != nil { |
| kind = MethodDecl |
| ast.Walk(x, n.Recv) |
| } |
| x.decl = n |
| x.visitIdent(kind, n.Name) |
| ast.Walk(x, n.Type) |
| if n.Body != nil { |
| ast.Walk(x, n.Body) |
| } |
| |
| case *ast.File: |
| x.visitComment(n.Doc) |
| x.decl = nil |
| x.visitIdent(PackageClause, n.Name) |
| for _, d := range n.Decls { |
| ast.Walk(x, d) |
| } |
| // don't visit package level comments for now |
| // to avoid duplicate visiting from individual |
| // nodes |
| |
| default: |
| return x |
| } |
| |
| return nil |
| } |
| |
| |
| func pkgName(filename string) string { |
| // use a new file set each time in order to not pollute the indexer's |
| // file set (which must stay in sync with the concatenated source code) |
| file, err := parser.ParseFile(token.NewFileSet(), filename, nil, parser.PackageClauseOnly) |
| if err != nil || file == nil { |
| return "" |
| } |
| return file.Name.Name |
| } |
| |
| |
| // addFile adds a file to the index if possible and returns the file set file |
| // and the file's AST if it was successfully parsed as a Go file. If addFile |
| // failed (that is, if the file was not added), it returns file == nil. |
| func (x *Indexer) addFile(filename string, goFile bool) (file *token.File, ast *ast.File) { |
| // open file |
| f, err := os.Open(filename, os.O_RDONLY, 0) |
| if err != nil { |
| return |
| } |
| defer f.Close() |
| |
| // The file set's base offset and x.sources size must be in lock-step; |
| // this permits the direct mapping of suffix array lookup results to |
| // to corresponding Pos values. |
| // |
| // When a file is added to the file set, it's offset base increases by |
| // the size of the file + 1; and the initial base offset is 1. Add an |
| // extra byte to the sources here. |
| x.sources.WriteByte(0) |
| |
| // If the sources length doesn't match the file set base at this point |
| // the file set implementation changed or we have another error. |
| base := x.fset.Base() |
| if x.sources.Len() != base { |
| panic("internal error - file base incorrect") |
| } |
| |
| // append file contents (src) to x.sources |
| if _, err := x.sources.ReadFrom(f); err == nil { |
| src := x.sources.Bytes()[base:] |
| |
| if goFile { |
| // parse the file and in the process add it to the file set |
| if ast, err = parser.ParseFile(x.fset, filename, src, parser.ParseComments); err == nil { |
| file = x.fset.File(ast.Pos()) // ast.Pos() is inside the file |
| return |
| } |
| // file has parse errors, and the AST may be incorrect - |
| // set lines information explicitly and index as ordinary |
| // text file (cannot fall through to the text case below |
| // because the file has already been added to the file set |
| // by the parser) |
| file = x.fset.File(token.Pos(base)) // token.Pos(base) is inside the file |
| file.SetLinesForContent(src) |
| ast = nil |
| return |
| } |
| |
| if isText(src) { |
| // only add the file to the file set (for the full text index) |
| file = x.fset.AddFile(filename, x.fset.Base(), len(src)) |
| file.SetLinesForContent(src) |
| return |
| } |
| } |
| |
| // discard possibly added data |
| x.sources.Truncate(base - 1) // -1 to remove added byte 0 since no file was added |
| return |
| } |
| |
| |
| // Design note: Using an explicit white list of permitted files for indexing |
| // makes sure that the important files are included and massively reduces the |
| // number of files to index. The advantage over a blacklist is that unexpected |
| // (non-blacklisted) files won't suddenly explode the index. |
| // |
| // TODO(gri): We may want to make this list customizable, perhaps via a flag. |
| |
| // Files are whitelisted if they have a file name or extension |
| // present as key in whitelisted. |
| var whitelisted = map[string]bool{ |
| ".bash": true, |
| ".c": true, |
| ".css": true, |
| ".go": true, |
| ".goc": true, |
| ".h": true, |
| ".html": true, |
| ".js": true, |
| ".out": true, |
| ".py": true, |
| ".s": true, |
| ".sh": true, |
| ".txt": true, |
| ".xml": true, |
| "AUTHORS": true, |
| "CONTRIBUTORS": true, |
| "LICENSE": true, |
| "Makefile": true, |
| "PATENTS": true, |
| "README": true, |
| } |
| |
| |
| // isWhitelisted returns true if a file is on the list |
| // of "permitted" files for indexing. The filename must |
| // be the directory-local name of the file. |
| func isWhitelisted(filename string) bool { |
| key := path.Ext(filename) |
| if key == "" { |
| // file has no extension - use entire filename |
| key = filename |
| } |
| return whitelisted[key] |
| } |
| |
| |
| func (x *Indexer) visitFile(dirname string, f *os.FileInfo, fulltextIndex bool) { |
| if !f.IsRegular() { |
| return |
| } |
| |
| filename := path.Join(dirname, f.Name) |
| goFile := false |
| |
| switch { |
| case isGoFile(f): |
| if !includeTestFiles && (!isPkgFile(f) || strings.HasPrefix(filename, "test/")) { |
| return |
| } |
| if !includeMainPackages && pkgName(filename) == "main" { |
| return |
| } |
| goFile = true |
| |
| case !fulltextIndex || !isWhitelisted(f.Name): |
| return |
| } |
| |
| file, fast := x.addFile(filename, goFile) |
| if file == nil { |
| return // addFile failed |
| } |
| |
| if fast != nil { |
| // we've got a Go file to index |
| x.current = file |
| dir, _ := path.Split(filename) |
| pak := Pak{dir, fast.Name.Name} |
| x.file = &File{filename, pak} |
| ast.Walk(x, fast) |
| } |
| |
| // update statistics |
| x.stats.Bytes += file.Size() |
| x.stats.Files++ |
| x.stats.Lines += file.LineCount() |
| } |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Index |
| |
| type LookupResult struct { |
| Decls HitList // package-level declarations (with snippets) |
| Others HitList // all other occurrences |
| } |
| |
| |
| type Index struct { |
| fset *token.FileSet // file set used during indexing; nil if no textindex |
| suffixes *suffixarray.Index // suffixes for concatenated sources; nil if no textindex |
| words map[string]*LookupResult // maps words to hit lists |
| alts map[string]*AltWords // maps canonical(words) to lists of alternative spellings |
| snippets []*Snippet // all snippets, indexed by snippet index |
| stats Statistics |
| } |
| |
| |
| func canonical(w string) string { return strings.ToLower(w) } |
| |
| |
| // NewIndex creates a new index for the .go files |
| // in the directories given by dirnames. |
| // |
| func NewIndex(dirnames <-chan string, fulltextIndex bool) *Index { |
| var x Indexer |
| |
| // initialize Indexer |
| x.fset = token.NewFileSet() |
| x.words = make(map[string]*IndexResult) |
| |
| // index all files in the directories given by dirnames |
| for dirname := range dirnames { |
| list, err := ioutil.ReadDir(dirname) |
| if err != nil { |
| continue // ignore this directory |
| } |
| for _, f := range list { |
| if !f.IsDirectory() { |
| x.visitFile(dirname, f, fulltextIndex) |
| } |
| } |
| } |
| |
| if !fulltextIndex { |
| // the file set, the current file, and the sources are |
| // not needed after indexing if no text index is built - |
| // help GC and clear them |
| x.fset = nil |
| x.sources.Reset() |
| x.current = nil // contains reference to fset! |
| } |
| |
| // for each word, reduce the RunLists into a LookupResult; |
| // also collect the word with its canonical spelling in a |
| // word list for later computation of alternative spellings |
| words := make(map[string]*LookupResult) |
| var wlist RunList |
| for w, h := range x.words { |
| decls := reduce(&h.Decls) |
| others := reduce(&h.Others) |
| words[w] = &LookupResult{ |
| Decls: decls, |
| Others: others, |
| } |
| wlist.Push(&wordPair{canonical(w), w}) |
| } |
| x.stats.Words = len(words) |
| |
| // reduce the word list {canonical(w), w} into |
| // a list of AltWords runs {canonical(w), {w}} |
| alist := wlist.reduce(lessWordPair, newAltWords) |
| |
| // convert alist into a map of alternative spellings |
| alts := make(map[string]*AltWords) |
| for i := 0; i < alist.Len(); i++ { |
| a := alist.At(i).(*AltWords) |
| alts[a.Canon] = a |
| } |
| |
| // convert snippet vector into a list |
| snippets := make([]*Snippet, x.snippets.Len()) |
| for i := 0; i < x.snippets.Len(); i++ { |
| snippets[i] = x.snippets.At(i).(*Snippet) |
| } |
| |
| // create text index |
| var suffixes *suffixarray.Index |
| if fulltextIndex { |
| suffixes = suffixarray.New(x.sources.Bytes()) |
| } |
| |
| return &Index{x.fset, suffixes, words, alts, snippets, x.stats} |
| } |
| |
| |
| // Stats() returns index statistics. |
| func (x *Index) Stats() Statistics { |
| return x.stats |
| } |
| |
| |
| func (x *Index) LookupWord(w string) (match *LookupResult, alt *AltWords) { |
| match = x.words[w] |
| alt = x.alts[canonical(w)] |
| // remove current spelling from alternatives |
| // (if there is no match, the alternatives do |
| // not contain the current spelling) |
| if match != nil && alt != nil { |
| alt = alt.filter(w) |
| } |
| return |
| } |
| |
| |
| func isIdentifier(s string) bool { |
| var S scanner.Scanner |
| fset := token.NewFileSet() |
| S.Init(fset.AddFile("", fset.Base(), len(s)), []byte(s), nil, 0) |
| if _, tok, _ := S.Scan(); tok == token.IDENT { |
| _, tok, _ := S.Scan() |
| return tok == token.EOF |
| } |
| return false |
| } |
| |
| |
| // For a given query, which is either a single identifier or a qualified |
| // identifier, Lookup returns a LookupResult, and a list of alternative |
| // spellings, if any. If the query syntax is wrong, an error is reported. |
| func (x *Index) Lookup(query string) (match *LookupResult, alt *AltWords, err os.Error) { |
| ss := strings.Split(query, ".", -1) |
| |
| // check query syntax |
| for _, s := range ss { |
| if !isIdentifier(s) { |
| err = os.NewError("all query parts must be identifiers") |
| return |
| } |
| } |
| |
| switch len(ss) { |
| case 1: |
| match, alt = x.LookupWord(ss[0]) |
| |
| case 2: |
| pakname := ss[0] |
| match, alt = x.LookupWord(ss[1]) |
| if match != nil { |
| // found a match - filter by package name |
| decls := match.Decls.filter(pakname) |
| others := match.Others.filter(pakname) |
| match = &LookupResult{decls, others} |
| } |
| |
| default: |
| err = os.NewError("query is not a (qualified) identifier") |
| } |
| |
| return |
| } |
| |
| |
| func (x *Index) Snippet(i int) *Snippet { |
| // handle illegal snippet indices gracefully |
| if 0 <= i && i < len(x.snippets) { |
| return x.snippets[i] |
| } |
| return nil |
| } |
| |
| |
| type positionList []struct { |
| filename string |
| line int |
| } |
| |
| func (list positionList) Len() int { return len(list) } |
| func (list positionList) Less(i, j int) bool { return list[i].filename < list[j].filename } |
| func (list positionList) Swap(i, j int) { list[i], list[j] = list[j], list[i] } |
| |
| |
| // unique returns the list sorted and with duplicate entries removed |
| func unique(list []int) []int { |
| sort.SortInts(list) |
| var last int |
| i := 0 |
| for _, x := range list { |
| if i == 0 || x != last { |
| last = x |
| list[i] = x |
| i++ |
| } |
| } |
| return list[0:i] |
| } |
| |
| |
| // A FileLines value specifies a file and line numbers within that file. |
| type FileLines struct { |
| Filename string |
| Lines []int |
| } |
| |
| |
| // LookupRegexp returns the number of matches and the matches where a regular |
| // expression r is found in the full text index. At most n matches are |
| // returned (thus found <= n). |
| // |
| func (x *Index) LookupRegexp(r *regexp.Regexp, n int) (found int, result []FileLines) { |
| if x.suffixes == nil || n <= 0 { |
| return |
| } |
| // n > 0 |
| |
| var list positionList |
| // FindAllIndex may returns matches that span across file boundaries. |
| // Such matches are unlikely, buf after eliminating them we may end up |
| // with fewer than n matches. If we don't have enough at the end, redo |
| // the search with an increased value n1, but only if FindAllIndex |
| // returned all the requested matches in the first place (if it |
| // returned fewer than that there cannot be more). |
| for n1 := n; found < n; n1 += n - found { |
| found = 0 |
| matches := x.suffixes.FindAllIndex(r, n1) |
| // compute files, exclude matches that span file boundaries, |
| // and map offsets to file-local offsets |
| list = make(positionList, len(matches)) |
| for _, m := range matches { |
| // by construction, an offset corresponds to the Pos value |
| // for the file set - use it to get the file and line |
| p := token.Pos(m[0]) |
| if file := x.fset.File(p); file != nil { |
| if base := file.Base(); base <= m[1] && m[1] <= base+file.Size() { |
| // match [m[0], m[1]) is within the file boundaries |
| list[found].filename = file.Name() |
| list[found].line = file.Line(p) |
| found++ |
| } |
| } |
| } |
| if found == n || len(matches) < n1 { |
| // found all matches or there's no chance to find more |
| break |
| } |
| } |
| list = list[0:found] |
| sort.Sort(list) // sort by filename |
| |
| // collect matches belonging to the same file |
| var last string |
| var lines []int |
| addLines := func() { |
| if len(lines) > 0 { |
| // remove duplicate lines |
| result = append(result, FileLines{last, unique(lines)}) |
| lines = nil |
| } |
| } |
| for _, m := range list { |
| if m.filename != last { |
| addLines() |
| last = m.filename |
| } |
| lines = append(lines, m.line) |
| } |
| addLines() |
| |
| return |
| } |