diff options
Diffstat (limited to 'vendor/golang.org/x/net/html/atom/gen.go')
-rw-r--r-- | vendor/golang.org/x/net/html/atom/gen.go | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/html/atom/gen.go b/vendor/golang.org/x/net/html/atom/gen.go new file mode 100644 index 000000000..5d052781b --- /dev/null +++ b/vendor/golang.org/x/net/html/atom/gen.go @@ -0,0 +1,712 @@ +// Copyright 2012 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. + +// +build ignore + +//go:generate go run gen.go +//go:generate go run gen.go -test + +package main + +import ( + "bytes" + "flag" + "fmt" + "go/format" + "io/ioutil" + "math/rand" + "os" + "sort" + "strings" +) + +// identifier converts s to a Go exported identifier. +// It converts "div" to "Div" and "accept-charset" to "AcceptCharset". +func identifier(s string) string { + b := make([]byte, 0, len(s)) + cap := true + for _, c := range s { + if c == '-' { + cap = true + continue + } + if cap && 'a' <= c && c <= 'z' { + c -= 'a' - 'A' + } + cap = false + b = append(b, byte(c)) + } + return string(b) +} + +var test = flag.Bool("test", false, "generate table_test.go") + +func genFile(name string, buf *bytes.Buffer) { + b, err := format.Source(buf.Bytes()) + if err != nil { + fmt.Fprintln(os.Stderr, err) + os.Exit(1) + } + if err := ioutil.WriteFile(name, b, 0644); err != nil { + fmt.Fprintln(os.Stderr, err) + os.Exit(1) + } +} + +func main() { + flag.Parse() + + var all []string + all = append(all, elements...) + all = append(all, attributes...) + all = append(all, eventHandlers...) + all = append(all, extra...) + sort.Strings(all) + + // uniq - lists have dups + w := 0 + for _, s := range all { + if w == 0 || all[w-1] != s { + all[w] = s + w++ + } + } + all = all[:w] + + if *test { + var buf bytes.Buffer + fmt.Fprintln(&buf, "// Code generated by go generate gen.go; DO NOT EDIT.\n") + fmt.Fprintln(&buf, "//go:generate go run gen.go -test\n") + fmt.Fprintln(&buf, "package atom\n") + fmt.Fprintln(&buf, "var testAtomList = []string{") + for _, s := range all { + fmt.Fprintf(&buf, "\t%q,\n", s) + } + fmt.Fprintln(&buf, "}") + + genFile("table_test.go", &buf) + return + } + + // Find hash that minimizes table size. + var best *table + for i := 0; i < 1000000; i++ { + if best != nil && 1<<(best.k-1) < len(all) { + break + } + h := rand.Uint32() + for k := uint(0); k <= 16; k++ { + if best != nil && k >= best.k { + break + } + var t table + if t.init(h, k, all) { + best = &t + break + } + } + } + if best == nil { + fmt.Fprintf(os.Stderr, "failed to construct string table\n") + os.Exit(1) + } + + // Lay out strings, using overlaps when possible. + layout := append([]string{}, all...) + + // Remove strings that are substrings of other strings + for changed := true; changed; { + changed = false + for i, s := range layout { + if s == "" { + continue + } + for j, t := range layout { + if i != j && t != "" && strings.Contains(s, t) { + changed = true + layout[j] = "" + } + } + } + } + + // Join strings where one suffix matches another prefix. + for { + // Find best i, j, k such that layout[i][len-k:] == layout[j][:k], + // maximizing overlap length k. + besti := -1 + bestj := -1 + bestk := 0 + for i, s := range layout { + if s == "" { + continue + } + for j, t := range layout { + if i == j { + continue + } + for k := bestk + 1; k <= len(s) && k <= len(t); k++ { + if s[len(s)-k:] == t[:k] { + besti = i + bestj = j + bestk = k + } + } + } + } + if bestk > 0 { + layout[besti] += layout[bestj][bestk:] + layout[bestj] = "" + continue + } + break + } + + text := strings.Join(layout, "") + + atom := map[string]uint32{} + for _, s := range all { + off := strings.Index(text, s) + if off < 0 { + panic("lost string " + s) + } + atom[s] = uint32(off<<8 | len(s)) + } + + var buf bytes.Buffer + // Generate the Go code. + fmt.Fprintln(&buf, "// Code generated by go generate gen.go; DO NOT EDIT.\n") + fmt.Fprintln(&buf, "//go:generate go run gen.go\n") + fmt.Fprintln(&buf, "package atom\n\nconst (") + + // compute max len + maxLen := 0 + for _, s := range all { + if maxLen < len(s) { + maxLen = len(s) + } + fmt.Fprintf(&buf, "\t%s Atom = %#x\n", identifier(s), atom[s]) + } + fmt.Fprintln(&buf, ")\n") + + fmt.Fprintf(&buf, "const hash0 = %#x\n\n", best.h0) + fmt.Fprintf(&buf, "const maxAtomLen = %d\n\n", maxLen) + + fmt.Fprintf(&buf, "var table = [1<<%d]Atom{\n", best.k) + for i, s := range best.tab { + if s == "" { + continue + } + fmt.Fprintf(&buf, "\t%#x: %#x, // %s\n", i, atom[s], s) + } + fmt.Fprintf(&buf, "}\n") + datasize := (1 << best.k) * 4 + + fmt.Fprintln(&buf, "const atomText =") + textsize := len(text) + for len(text) > 60 { + fmt.Fprintf(&buf, "\t%q +\n", text[:60]) + text = text[60:] + } + fmt.Fprintf(&buf, "\t%q\n\n", text) + + genFile("table.go", &buf) + + fmt.Fprintf(os.Stdout, "%d atoms; %d string bytes + %d tables = %d total data\n", len(all), textsize, datasize, textsize+datasize) +} + +type byLen []string + +func (x byLen) Less(i, j int) bool { return len(x[i]) > len(x[j]) } +func (x byLen) Swap(i, j int) { x[i], x[j] = x[j], x[i] } +func (x byLen) Len() int { return len(x) } + +// fnv computes the FNV hash with an arbitrary starting value h. +func fnv(h uint32, s string) uint32 { + for i := 0; i < len(s); i++ { + h ^= uint32(s[i]) + h *= 16777619 + } + return h +} + +// A table represents an attempt at constructing the lookup table. +// The lookup table uses cuckoo hashing, meaning that each string +// can be found in one of two positions. +type table struct { + h0 uint32 + k uint + mask uint32 + tab []string +} + +// hash returns the two hashes for s. +func (t *table) hash(s string) (h1, h2 uint32) { + h := fnv(t.h0, s) + h1 = h & t.mask + h2 = (h >> 16) & t.mask + return +} + +// init initializes the table with the given parameters. +// h0 is the initial hash value, +// k is the number of bits of hash value to use, and +// x is the list of strings to store in the table. +// init returns false if the table cannot be constructed. +func (t *table) init(h0 uint32, k uint, x []string) bool { + t.h0 = h0 + t.k = k + t.tab = make([]string, 1<<k) + t.mask = 1<<k - 1 + for _, s := range x { + if !t.insert(s) { + return false + } + } + return true +} + +// insert inserts s in the table. +func (t *table) insert(s string) bool { + h1, h2 := t.hash(s) + if t.tab[h1] == "" { + t.tab[h1] = s + return true + } + if t.tab[h2] == "" { + t.tab[h2] = s + return true + } + if t.push(h1, 0) { + t.tab[h1] = s + return true + } + if t.push(h2, 0) { + t.tab[h2] = s + return true + } + return false +} + +// push attempts to push aside the entry in slot i. +func (t *table) push(i uint32, depth int) bool { + if depth > len(t.tab) { + return false + } + s := t.tab[i] + h1, h2 := t.hash(s) + j := h1 + h2 - i + if t.tab[j] != "" && !t.push(j, depth+1) { + return false + } + t.tab[j] = s + return true +} + +// The lists of element names and attribute keys were taken from +// https://html.spec.whatwg.org/multipage/indices.html#index +// as of the "HTML Living Standard - Last Updated 16 April 2018" version. + +// "command", "keygen" and "menuitem" have been removed from the spec, +// but are kept here for backwards compatibility. +var elements = []string{ + "a", + "abbr", + "address", + "area", + "article", + "aside", + "audio", + "b", + "base", + "bdi", + "bdo", + "blockquote", + "body", + "br", + "button", + "canvas", + "caption", + "cite", + "code", + "col", + "colgroup", + "command", + "data", + "datalist", + "dd", + "del", + "details", + "dfn", + "dialog", + "div", + "dl", + "dt", + "em", + "embed", + "fieldset", + "figcaption", + "figure", + "footer", + "form", + "h1", + "h2", + "h3", + "h4", + "h5", + "h6", + "head", + "header", + "hgroup", + "hr", + "html", + "i", + "iframe", + "img", + "input", + "ins", + "kbd", + "keygen", + "label", + "legend", + "li", + "link", + "main", + "map", + "mark", + "menu", + "menuitem", + "meta", + "meter", + "nav", + "noscript", + "object", + "ol", + "optgroup", + "option", + "output", + "p", + "param", + "picture", + "pre", + "progress", + "q", + "rp", + "rt", + "ruby", + "s", + "samp", + "script", + "section", + "select", + "slot", + "small", + "source", + "span", + "strong", + "style", + "sub", + "summary", + "sup", + "table", + "tbody", + "td", + "template", + "textarea", + "tfoot", + "th", + "thead", + "time", + "title", + "tr", + "track", + "u", + "ul", + "var", + "video", + "wbr", +} + +// https://html.spec.whatwg.org/multipage/indices.html#attributes-3 +// +// "challenge", "command", "contextmenu", "dropzone", "icon", "keytype", "mediagroup", +// "radiogroup", "spellcheck", "scoped", "seamless", "sortable" and "sorted" have been removed from the spec, +// but are kept here for backwards compatibility. +var attributes = []string{ + "abbr", + "accept", + "accept-charset", + "accesskey", + "action", + "allowfullscreen", + "allowpaymentrequest", + "allowusermedia", + "alt", + "as", + "async", + "autocomplete", + "autofocus", + "autoplay", + "challenge", + "charset", + "checked", + "cite", + "class", + "color", + "cols", + "colspan", + "command", + "content", + "contenteditable", + "contextmenu", + "controls", + "coords", + "crossorigin", + "data", + "datetime", + "default", + "defer", + "dir", + "dirname", + "disabled", + "download", + "draggable", + "dropzone", + "enctype", + "for", + "form", + "formaction", + "formenctype", + "formmethod", + "formnovalidate", + "formtarget", + "headers", + "height", + "hidden", + "high", + "href", + "hreflang", + "http-equiv", + "icon", + "id", + "inputmode", + "integrity", + "is", + "ismap", + "itemid", + "itemprop", + "itemref", + "itemscope", + "itemtype", + "keytype", + "kind", + "label", + "lang", + "list", + "loop", + "low", + "manifest", + "max", + "maxlength", + "media", + "mediagroup", + "method", + "min", + "minlength", + "multiple", + "muted", + "name", + "nomodule", + "nonce", + "novalidate", + "open", + "optimum", + "pattern", + "ping", + "placeholder", + "playsinline", + "poster", + "preload", + "radiogroup", + "readonly", + "referrerpolicy", + "rel", + "required", + "reversed", + "rows", + "rowspan", + "sandbox", + "spellcheck", + "scope", + "scoped", + "seamless", + "selected", + "shape", + "size", + "sizes", + "sortable", + "sorted", + "slot", + "span", + "spellcheck", + "src", + "srcdoc", + "srclang", + "srcset", + "start", + "step", + "style", + "tabindex", + "target", + "title", + "translate", + "type", + "typemustmatch", + "updateviacache", + "usemap", + "value", + "width", + "workertype", + "wrap", +} + +// "onautocomplete", "onautocompleteerror", "onmousewheel", +// "onshow" and "onsort" have been removed from the spec, +// but are kept here for backwards compatibility. +var eventHandlers = []string{ + "onabort", + "onautocomplete", + "onautocompleteerror", + "onauxclick", + "onafterprint", + "onbeforeprint", + "onbeforeunload", + "onblur", + "oncancel", + "oncanplay", + "oncanplaythrough", + "onchange", + "onclick", + "onclose", + "oncontextmenu", + "oncopy", + "oncuechange", + "oncut", + "ondblclick", + "ondrag", + "ondragend", + "ondragenter", + "ondragexit", + "ondragleave", + "ondragover", + "ondragstart", + "ondrop", + "ondurationchange", + "onemptied", + "onended", + "onerror", + "onfocus", + "onhashchange", + "oninput", + "oninvalid", + "onkeydown", + "onkeypress", + "onkeyup", + "onlanguagechange", + "onload", + "onloadeddata", + "onloadedmetadata", + "onloadend", + "onloadstart", + "onmessage", + "onmessageerror", + "onmousedown", + "onmouseenter", + "onmouseleave", + "onmousemove", + "onmouseout", + "onmouseover", + "onmouseup", + "onmousewheel", + "onwheel", + "onoffline", + "ononline", + "onpagehide", + "onpageshow", + "onpaste", + "onpause", + "onplay", + "onplaying", + "onpopstate", + "onprogress", + "onratechange", + "onreset", + "onresize", + "onrejectionhandled", + "onscroll", + "onsecuritypolicyviolation", + "onseeked", + "onseeking", + "onselect", + "onshow", + "onsort", + "onstalled", + "onstorage", + "onsubmit", + "onsuspend", + "ontimeupdate", + "ontoggle", + "onunhandledrejection", + "onunload", + "onvolumechange", + "onwaiting", +} + +// extra are ad-hoc values not covered by any of the lists above. +var extra = []string{ + "acronym", + "align", + "annotation", + "annotation-xml", + "applet", + "basefont", + "bgsound", + "big", + "blink", + "center", + "color", + "desc", + "face", + "font", + "foreignObject", // HTML is case-insensitive, but SVG-embedded-in-HTML is case-sensitive. + "foreignobject", + "frame", + "frameset", + "image", + "isindex", + "listing", + "malignmark", + "marquee", + "math", + "mglyph", + "mi", + "mn", + "mo", + "ms", + "mtext", + "nobr", + "noembed", + "noframes", + "plaintext", + "prompt", + "public", + "rb", + "rtc", + "spacer", + "strike", + "svg", + "system", + "tt", + "xmp", +} |