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author | Wim <wim@42.be> | 2017-02-18 23:00:46 +0100 |
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committer | Wim <wim@42.be> | 2017-02-18 23:11:48 +0100 |
commit | 930b639cc9cd2d2873302f30303378c0e53816a8 (patch) | |
tree | 8cd3f1d464fb5d4e5607fe16255c35a31a9d8b62 /vendor/github.com/valyala/fasttemplate/template.go | |
parent | 58483ea70c2c99a352592c5e50686fb03985650e (diff) | |
download | matterbridge-msglm-930b639cc9cd2d2873302f30303378c0e53816a8.tar.gz matterbridge-msglm-930b639cc9cd2d2873302f30303378c0e53816a8.tar.bz2 matterbridge-msglm-930b639cc9cd2d2873302f30303378c0e53816a8.zip |
Update vendor
Diffstat (limited to 'vendor/github.com/valyala/fasttemplate/template.go')
-rw-r--r-- | vendor/github.com/valyala/fasttemplate/template.go | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/vendor/github.com/valyala/fasttemplate/template.go b/vendor/github.com/valyala/fasttemplate/template.go new file mode 100644 index 00000000..91209201 --- /dev/null +++ b/vendor/github.com/valyala/fasttemplate/template.go @@ -0,0 +1,317 @@ +// Package fasttemplate implements simple and fast template library. +// +// Fasttemplate is faster than text/template, strings.Replace +// and strings.Replacer. +// +// Fasttemplate ideally fits for fast and simple placeholders' substitutions. +package fasttemplate + +import ( + "bytes" + "fmt" + "github.com/valyala/bytebufferpool" + "io" +) + +// ExecuteFunc calls f on each template tag (placeholder) occurrence. +// +// Returns the number of bytes written to w. +// +// This function is optimized for constantly changing templates. +// Use Template.ExecuteFunc for frozen templates. +func ExecuteFunc(template, startTag, endTag string, w io.Writer, f TagFunc) (int64, error) { + s := unsafeString2Bytes(template) + a := unsafeString2Bytes(startTag) + b := unsafeString2Bytes(endTag) + + var nn int64 + var ni int + var err error + for { + n := bytes.Index(s, a) + if n < 0 { + break + } + ni, err = w.Write(s[:n]) + nn += int64(ni) + if err != nil { + return nn, err + } + + s = s[n+len(a):] + n = bytes.Index(s, b) + if n < 0 { + // cannot find end tag - just write it to the output. + ni, _ = w.Write(a) + nn += int64(ni) + break + } + + ni, err = f(w, unsafeBytes2String(s[:n])) + nn += int64(ni) + s = s[n+len(b):] + } + ni, err = w.Write(s) + nn += int64(ni) + + return nn, err +} + +// Execute substitutes template tags (placeholders) with the corresponding +// values from the map m and writes the result to the given writer w. +// +// Substitution map m may contain values with the following types: +// * []byte - the fastest value type +// * string - convenient value type +// * TagFunc - flexible value type +// +// Returns the number of bytes written to w. +// +// This function is optimized for constantly changing templates. +// Use Template.Execute for frozen templates. +func Execute(template, startTag, endTag string, w io.Writer, m map[string]interface{}) (int64, error) { + return ExecuteFunc(template, startTag, endTag, w, func(w io.Writer, tag string) (int, error) { return stdTagFunc(w, tag, m) }) +} + +// ExecuteFuncString calls f on each template tag (placeholder) occurrence +// and substitutes it with the data written to TagFunc's w. +// +// Returns the resulting string. +// +// This function is optimized for constantly changing templates. +// Use Template.ExecuteFuncString for frozen templates. +func ExecuteFuncString(template, startTag, endTag string, f TagFunc) string { + tagsCount := bytes.Count(unsafeString2Bytes(template), unsafeString2Bytes(startTag)) + if tagsCount == 0 { + return template + } + + bb := byteBufferPool.Get() + if _, err := ExecuteFunc(template, startTag, endTag, bb, f); err != nil { + panic(fmt.Sprintf("unexpected error: %s", err)) + } + s := string(bb.B) + bb.Reset() + byteBufferPool.Put(bb) + return s +} + +var byteBufferPool bytebufferpool.Pool + +// ExecuteString substitutes template tags (placeholders) with the corresponding +// values from the map m and returns the result. +// +// Substitution map m may contain values with the following types: +// * []byte - the fastest value type +// * string - convenient value type +// * TagFunc - flexible value type +// +// This function is optimized for constantly changing templates. +// Use Template.ExecuteString for frozen templates. +func ExecuteString(template, startTag, endTag string, m map[string]interface{}) string { + return ExecuteFuncString(template, startTag, endTag, func(w io.Writer, tag string) (int, error) { return stdTagFunc(w, tag, m) }) +} + +// Template implements simple template engine, which can be used for fast +// tags' (aka placeholders) substitution. +type Template struct { + template string + startTag string + endTag string + + texts [][]byte + tags []string + byteBufferPool bytebufferpool.Pool +} + +// New parses the given template using the given startTag and endTag +// as tag start and tag end. +// +// The returned template can be executed by concurrently running goroutines +// using Execute* methods. +// +// New panics if the given template cannot be parsed. Use NewTemplate instead +// if template may contain errors. +func New(template, startTag, endTag string) *Template { + t, err := NewTemplate(template, startTag, endTag) + if err != nil { + panic(err) + } + return t +} + +// NewTemplate parses the given template using the given startTag and endTag +// as tag start and tag end. +// +// The returned template can be executed by concurrently running goroutines +// using Execute* methods. +func NewTemplate(template, startTag, endTag string) (*Template, error) { + var t Template + err := t.Reset(template, startTag, endTag) + if err != nil { + return nil, err + } + return &t, nil +} + +// TagFunc can be used as a substitution value in the map passed to Execute*. +// Execute* functions pass tag (placeholder) name in 'tag' argument. +// +// TagFunc must be safe to call from concurrently running goroutines. +// +// TagFunc must write contents to w and return the number of bytes written. +type TagFunc func(w io.Writer, tag string) (int, error) + +// Reset resets the template t to new one defined by +// template, startTag and endTag. +// +// Reset allows Template object re-use. +// +// Reset may be called only if no other goroutines call t methods at the moment. +func (t *Template) Reset(template, startTag, endTag string) error { + // Keep these vars in t, so GC won't collect them and won't break + // vars derived via unsafe* + t.template = template + t.startTag = startTag + t.endTag = endTag + t.texts = t.texts[:0] + t.tags = t.tags[:0] + + if len(startTag) == 0 { + panic("startTag cannot be empty") + } + if len(endTag) == 0 { + panic("endTag cannot be empty") + } + + s := unsafeString2Bytes(template) + a := unsafeString2Bytes(startTag) + b := unsafeString2Bytes(endTag) + + tagsCount := bytes.Count(s, a) + if tagsCount == 0 { + return nil + } + + if tagsCount+1 > cap(t.texts) { + t.texts = make([][]byte, 0, tagsCount+1) + } + if tagsCount > cap(t.tags) { + t.tags = make([]string, 0, tagsCount) + } + + for { + n := bytes.Index(s, a) + if n < 0 { + t.texts = append(t.texts, s) + break + } + t.texts = append(t.texts, s[:n]) + + s = s[n+len(a):] + n = bytes.Index(s, b) + if n < 0 { + return fmt.Errorf("Cannot find end tag=%q in the template=%q starting from %q", endTag, template, s) + } + + t.tags = append(t.tags, unsafeBytes2String(s[:n])) + s = s[n+len(b):] + } + + return nil +} + +// ExecuteFunc calls f on each template tag (placeholder) occurrence. +// +// Returns the number of bytes written to w. +// +// This function is optimized for frozen templates. +// Use ExecuteFunc for constantly changing templates. +func (t *Template) ExecuteFunc(w io.Writer, f TagFunc) (int64, error) { + var nn int64 + + n := len(t.texts) - 1 + if n == -1 { + ni, err := w.Write(unsafeString2Bytes(t.template)) + return int64(ni), err + } + + for i := 0; i < n; i++ { + ni, err := w.Write(t.texts[i]) + nn += int64(ni) + if err != nil { + return nn, err + } + + ni, err = f(w, t.tags[i]) + nn += int64(ni) + if err != nil { + return nn, err + } + } + ni, err := w.Write(t.texts[n]) + nn += int64(ni) + return nn, err +} + +// Execute substitutes template tags (placeholders) with the corresponding +// values from the map m and writes the result to the given writer w. +// +// Substitution map m may contain values with the following types: +// * []byte - the fastest value type +// * string - convenient value type +// * TagFunc - flexible value type +// +// Returns the number of bytes written to w. +func (t *Template) Execute(w io.Writer, m map[string]interface{}) (int64, error) { + return t.ExecuteFunc(w, func(w io.Writer, tag string) (int, error) { return stdTagFunc(w, tag, m) }) +} + +// ExecuteFuncString calls f on each template tag (placeholder) occurrence +// and substitutes it with the data written to TagFunc's w. +// +// Returns the resulting string. +// +// This function is optimized for frozen templates. +// Use ExecuteFuncString for constantly changing templates. +func (t *Template) ExecuteFuncString(f TagFunc) string { + bb := t.byteBufferPool.Get() + if _, err := t.ExecuteFunc(bb, f); err != nil { + panic(fmt.Sprintf("unexpected error: %s", err)) + } + s := string(bb.Bytes()) + bb.Reset() + t.byteBufferPool.Put(bb) + return s +} + +// ExecuteString substitutes template tags (placeholders) with the corresponding +// values from the map m and returns the result. +// +// Substitution map m may contain values with the following types: +// * []byte - the fastest value type +// * string - convenient value type +// * TagFunc - flexible value type +// +// This function is optimized for frozen templates. +// Use ExecuteString for constantly changing templates. +func (t *Template) ExecuteString(m map[string]interface{}) string { + return t.ExecuteFuncString(func(w io.Writer, tag string) (int, error) { return stdTagFunc(w, tag, m) }) +} + +func stdTagFunc(w io.Writer, tag string, m map[string]interface{}) (int, error) { + v := m[tag] + if v == nil { + return 0, nil + } + switch value := v.(type) { + case []byte: + return w.Write(value) + case string: + return w.Write([]byte(value)) + case TagFunc: + return value(w, tag) + default: + panic(fmt.Sprintf("tag=%q contains unexpected value type=%#v. Expected []byte, string or TagFunc", tag, v)) + } +} |