diff options
Diffstat (limited to 'vendor/golang.org')
| -rw-r--r-- | vendor/golang.org/x/text/AUTHORS | 3 | ||||
| -rw-r--r-- | vendor/golang.org/x/text/CONTRIBUTORS | 3 | ||||
| -rw-r--r-- | vendor/golang.org/x/text/LICENSE | 27 | ||||
| -rw-r--r-- | vendor/golang.org/x/text/PATENTS | 22 | ||||
| -rw-r--r-- | vendor/golang.org/x/text/runes/cond.go | 187 | ||||
| -rw-r--r-- | vendor/golang.org/x/text/runes/runes.go | 355 | ||||
| -rw-r--r-- | vendor/golang.org/x/text/transform/transform.go | 705 |
7 files changed, 1302 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/AUTHORS b/vendor/golang.org/x/text/AUTHORS new file mode 100644 index 00000000..15167cd7 --- /dev/null +++ b/vendor/golang.org/x/text/AUTHORS @@ -0,0 +1,3 @@ +# This source code refers to The Go Authors for copyright purposes. +# The master list of authors is in the main Go distribution, +# visible at http://tip.golang.org/AUTHORS. diff --git a/vendor/golang.org/x/text/CONTRIBUTORS b/vendor/golang.org/x/text/CONTRIBUTORS new file mode 100644 index 00000000..1c4577e9 --- /dev/null +++ b/vendor/golang.org/x/text/CONTRIBUTORS @@ -0,0 +1,3 @@ +# This source code was written by the Go contributors. +# The master list of contributors is in the main Go distribution, +# visible at http://tip.golang.org/CONTRIBUTORS. diff --git a/vendor/golang.org/x/text/LICENSE b/vendor/golang.org/x/text/LICENSE new file mode 100644 index 00000000..6a66aea5 --- /dev/null +++ b/vendor/golang.org/x/text/LICENSE @@ -0,0 +1,27 @@ +Copyright (c) 2009 The Go Authors. All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + * Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + * Neither the name of Google Inc. nor the names of its +contributors may be used to endorse or promote products derived from +this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/vendor/golang.org/x/text/PATENTS b/vendor/golang.org/x/text/PATENTS new file mode 100644 index 00000000..73309904 --- /dev/null +++ b/vendor/golang.org/x/text/PATENTS @@ -0,0 +1,22 @@ +Additional IP Rights Grant (Patents) + +"This implementation" means the copyrightable works distributed by +Google as part of the Go project. + +Google hereby grants to You a perpetual, worldwide, non-exclusive, +no-charge, royalty-free, irrevocable (except as stated in this section) +patent license to make, have made, use, offer to sell, sell, import, +transfer and otherwise run, modify and propagate the contents of this +implementation of Go, where such license applies only to those patent +claims, both currently owned or controlled by Google and acquired in +the future, licensable by Google that are necessarily infringed by this +implementation of Go. This grant does not include claims that would be +infringed only as a consequence of further modification of this +implementation. If you or your agent or exclusive licensee institute or +order or agree to the institution of patent litigation against any +entity (including a cross-claim or counterclaim in a lawsuit) alleging +that this implementation of Go or any code incorporated within this +implementation of Go constitutes direct or contributory patent +infringement, or inducement of patent infringement, then any patent +rights granted to you under this License for this implementation of Go +shall terminate as of the date such litigation is filed. diff --git a/vendor/golang.org/x/text/runes/cond.go b/vendor/golang.org/x/text/runes/cond.go new file mode 100644 index 00000000..df7aa02d --- /dev/null +++ b/vendor/golang.org/x/text/runes/cond.go @@ -0,0 +1,187 @@ +// Copyright 2015 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. + +package runes + +import ( + "unicode/utf8" + + "golang.org/x/text/transform" +) + +// Note: below we pass invalid UTF-8 to the tIn and tNotIn transformers as is. +// This is done for various reasons: +// - To retain the semantics of the Nop transformer: if input is passed to a Nop +// one would expect it to be unchanged. +// - It would be very expensive to pass a converted RuneError to a transformer: +// a transformer might need more source bytes after RuneError, meaning that +// the only way to pass it safely is to create a new buffer and manage the +// intermingling of RuneErrors and normal input. +// - Many transformers leave ill-formed UTF-8 as is, so this is not +// inconsistent. Generally ill-formed UTF-8 is only replaced if it is a +// logical consequence of the operation (as for Map) or if it otherwise would +// pose security concerns (as for Remove). +// - An alternative would be to return an error on ill-formed UTF-8, but this +// would be inconsistent with other operations. + +// If returns a transformer that applies tIn to consecutive runes for which +// s.Contains(r) and tNotIn to consecutive runes for which !s.Contains(r). Reset +// is called on tIn and tNotIn at the start of each run. A Nop transformer will +// substitute a nil value passed to tIn or tNotIn. Invalid UTF-8 is translated +// to RuneError to determine which transformer to apply, but is passed as is to +// the respective transformer. +func If(s Set, tIn, tNotIn transform.Transformer) Transformer { + if tIn == nil && tNotIn == nil { + return Transformer{transform.Nop} + } + if tIn == nil { + tIn = transform.Nop + } + if tNotIn == nil { + tNotIn = transform.Nop + } + sIn, ok := tIn.(transform.SpanningTransformer) + if !ok { + sIn = dummySpan{tIn} + } + sNotIn, ok := tNotIn.(transform.SpanningTransformer) + if !ok { + sNotIn = dummySpan{tNotIn} + } + + a := &cond{ + tIn: sIn, + tNotIn: sNotIn, + f: s.Contains, + } + a.Reset() + return Transformer{a} +} + +type dummySpan struct{ transform.Transformer } + +func (d dummySpan) Span(src []byte, atEOF bool) (n int, err error) { + return 0, transform.ErrEndOfSpan +} + +type cond struct { + tIn, tNotIn transform.SpanningTransformer + f func(rune) bool + check func(rune) bool // current check to perform + t transform.SpanningTransformer // current transformer to use +} + +// Reset implements transform.Transformer. +func (t *cond) Reset() { + t.check = t.is + t.t = t.tIn + t.t.Reset() // notIn will be reset on first usage. +} + +func (t *cond) is(r rune) bool { + if t.f(r) { + return true + } + t.check = t.isNot + t.t = t.tNotIn + t.tNotIn.Reset() + return false +} + +func (t *cond) isNot(r rune) bool { + if !t.f(r) { + return true + } + t.check = t.is + t.t = t.tIn + t.tIn.Reset() + return false +} + +// This implementation of Span doesn't help all too much, but it needs to be +// there to satisfy this package's Transformer interface. +// TODO: there are certainly room for improvements, though. For example, if +// t.t == transform.Nop (which will a common occurrence) it will save a bundle +// to special-case that loop. +func (t *cond) Span(src []byte, atEOF bool) (n int, err error) { + p := 0 + for n < len(src) && err == nil { + // Don't process too much at a time as the Spanner that will be + // called on this block may terminate early. + const maxChunk = 4096 + max := len(src) + if v := n + maxChunk; v < max { + max = v + } + atEnd := false + size := 0 + current := t.t + for ; p < max; p += size { + r := rune(src[p]) + if r < utf8.RuneSelf { + size = 1 + } else if r, size = utf8.DecodeRune(src[p:]); size == 1 { + if !atEOF && !utf8.FullRune(src[p:]) { + err = transform.ErrShortSrc + break + } + } + if !t.check(r) { + // The next rune will be the start of a new run. + atEnd = true + break + } + } + n2, err2 := current.Span(src[n:p], atEnd || (atEOF && p == len(src))) + n += n2 + if err2 != nil { + return n, err2 + } + // At this point either err != nil or t.check will pass for the rune at p. + p = n + size + } + return n, err +} + +func (t *cond) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + p := 0 + for nSrc < len(src) && err == nil { + // Don't process too much at a time, as the work might be wasted if the + // destination buffer isn't large enough to hold the result or a + // transform returns an error early. + const maxChunk = 4096 + max := len(src) + if n := nSrc + maxChunk; n < len(src) { + max = n + } + atEnd := false + size := 0 + current := t.t + for ; p < max; p += size { + r := rune(src[p]) + if r < utf8.RuneSelf { + size = 1 + } else if r, size = utf8.DecodeRune(src[p:]); size == 1 { + if !atEOF && !utf8.FullRune(src[p:]) { + err = transform.ErrShortSrc + break + } + } + if !t.check(r) { + // The next rune will be the start of a new run. + atEnd = true + break + } + } + nDst2, nSrc2, err2 := current.Transform(dst[nDst:], src[nSrc:p], atEnd || (atEOF && p == len(src))) + nDst += nDst2 + nSrc += nSrc2 + if err2 != nil { + return nDst, nSrc, err2 + } + // At this point either err != nil or t.check will pass for the rune at p. + p = nSrc + size + } + return nDst, nSrc, err +} diff --git a/vendor/golang.org/x/text/runes/runes.go b/vendor/golang.org/x/text/runes/runes.go new file mode 100644 index 00000000..71933696 --- /dev/null +++ b/vendor/golang.org/x/text/runes/runes.go @@ -0,0 +1,355 @@ +// Copyright 2014 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. + +// Package runes provide transforms for UTF-8 encoded text. +package runes // import "golang.org/x/text/runes" + +import ( + "unicode" + "unicode/utf8" + + "golang.org/x/text/transform" +) + +// A Set is a collection of runes. +type Set interface { + // Contains returns true if r is contained in the set. + Contains(r rune) bool +} + +type setFunc func(rune) bool + +func (s setFunc) Contains(r rune) bool { + return s(r) +} + +// Note: using funcs here instead of wrapping types result in cleaner +// documentation and a smaller API. + +// In creates a Set with a Contains method that returns true for all runes in +// the given RangeTable. +func In(rt *unicode.RangeTable) Set { + return setFunc(func(r rune) bool { return unicode.Is(rt, r) }) +} + +// In creates a Set with a Contains method that returns true for all runes not +// in the given RangeTable. +func NotIn(rt *unicode.RangeTable) Set { + return setFunc(func(r rune) bool { return !unicode.Is(rt, r) }) +} + +// Predicate creates a Set with a Contains method that returns f(r). +func Predicate(f func(rune) bool) Set { + return setFunc(f) +} + +// Transformer implements the transform.Transformer interface. +type Transformer struct { + t transform.SpanningTransformer +} + +func (t Transformer) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + return t.t.Transform(dst, src, atEOF) +} + +func (t Transformer) Span(b []byte, atEOF bool) (n int, err error) { + return t.t.Span(b, atEOF) +} + +func (t Transformer) Reset() { t.t.Reset() } + +// Bytes returns a new byte slice with the result of converting b using t. It +// calls Reset on t. It returns nil if any error was found. This can only happen +// if an error-producing Transformer is passed to If. +func (t Transformer) Bytes(b []byte) []byte { + b, _, err := transform.Bytes(t, b) + if err != nil { + return nil + } + return b +} + +// String returns a string with the result of converting s using t. It calls +// Reset on t. It returns the empty string if any error was found. This can only +// happen if an error-producing Transformer is passed to If. +func (t Transformer) String(s string) string { + s, _, err := transform.String(t, s) + if err != nil { + return "" + } + return s +} + +// TODO: +// - Copy: copying strings and bytes in whole-rune units. +// - Validation (maybe) +// - Well-formed-ness (maybe) + +const runeErrorString = string(utf8.RuneError) + +// Remove returns a Transformer that removes runes r for which s.Contains(r). +// Illegal input bytes are replaced by RuneError before being passed to f. +func Remove(s Set) Transformer { + if f, ok := s.(setFunc); ok { + // This little trick cuts the running time of BenchmarkRemove for sets + // created by Predicate roughly in half. + // TODO: special-case RangeTables as well. + return Transformer{remove(f)} + } + return Transformer{remove(s.Contains)} +} + +// TODO: remove transform.RemoveFunc. + +type remove func(r rune) bool + +func (remove) Reset() {} + +// Span implements transform.Spanner. +func (t remove) Span(src []byte, atEOF bool) (n int, err error) { + for r, size := rune(0), 0; n < len(src); { + if r = rune(src[n]); r < utf8.RuneSelf { + size = 1 + } else if r, size = utf8.DecodeRune(src[n:]); size == 1 { + // Invalid rune. + if !atEOF && !utf8.FullRune(src[n:]) { + err = transform.ErrShortSrc + } else { + err = transform.ErrEndOfSpan + } + break + } + if t(r) { + err = transform.ErrEndOfSpan + break + } + n += size + } + return +} + +// Transform implements transform.Transformer. +func (t remove) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + for r, size := rune(0), 0; nSrc < len(src); { + if r = rune(src[nSrc]); r < utf8.RuneSelf { + size = 1 + } else if r, size = utf8.DecodeRune(src[nSrc:]); size == 1 { + // Invalid rune. + if !atEOF && !utf8.FullRune(src[nSrc:]) { + err = transform.ErrShortSrc + break + } + // We replace illegal bytes with RuneError. Not doing so might + // otherwise turn a sequence of invalid UTF-8 into valid UTF-8. + // The resulting byte sequence may subsequently contain runes + // for which t(r) is true that were passed unnoticed. + if !t(utf8.RuneError) { + if nDst+3 > len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst+0] = runeErrorString[0] + dst[nDst+1] = runeErrorString[1] + dst[nDst+2] = runeErrorString[2] + nDst += 3 + } + nSrc++ + continue + } + if t(r) { + nSrc += size + continue + } + if nDst+size > len(dst) { + err = transform.ErrShortDst + break + } + for i := 0; i < size; i++ { + dst[nDst] = src[nSrc] + nDst++ + nSrc++ + } + } + return +} + +// Map returns a Transformer that maps the runes in the input using the given +// mapping. Illegal bytes in the input are converted to utf8.RuneError before +// being passed to the mapping func. +func Map(mapping func(rune) rune) Transformer { + return Transformer{mapper(mapping)} +} + +type mapper func(rune) rune + +func (mapper) Reset() {} + +// Span implements transform.Spanner. +func (t mapper) Span(src []byte, atEOF bool) (n int, err error) { + for r, size := rune(0), 0; n < len(src); n += size { + if r = rune(src[n]); r < utf8.RuneSelf { + size = 1 + } else if r, size = utf8.DecodeRune(src[n:]); size == 1 { + // Invalid rune. + if !atEOF && !utf8.FullRune(src[n:]) { + err = transform.ErrShortSrc + } else { + err = transform.ErrEndOfSpan + } + break + } + if t(r) != r { + err = transform.ErrEndOfSpan + break + } + } + return n, err +} + +// Transform implements transform.Transformer. +func (t mapper) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + var replacement rune + var b [utf8.UTFMax]byte + + for r, size := rune(0), 0; nSrc < len(src); { + if r = rune(src[nSrc]); r < utf8.RuneSelf { + if replacement = t(r); replacement < utf8.RuneSelf { + if nDst == len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst] = byte(replacement) + nDst++ + nSrc++ + continue + } + size = 1 + } else if r, size = utf8.DecodeRune(src[nSrc:]); size == 1 { + // Invalid rune. + if !atEOF && !utf8.FullRune(src[nSrc:]) { + err = transform.ErrShortSrc + break + } + + if replacement = t(utf8.RuneError); replacement == utf8.RuneError { + if nDst+3 > len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst+0] = runeErrorString[0] + dst[nDst+1] = runeErrorString[1] + dst[nDst+2] = runeErrorString[2] + nDst += 3 + nSrc++ + continue + } + } else if replacement = t(r); replacement == r { + if nDst+size > len(dst) { + err = transform.ErrShortDst + break + } + for i := 0; i < size; i++ { + dst[nDst] = src[nSrc] + nDst++ + nSrc++ + } + continue + } + + n := utf8.EncodeRune(b[:], replacement) + + if nDst+n > len(dst) { + err = transform.ErrShortDst + break + } + for i := 0; i < n; i++ { + dst[nDst] = b[i] + nDst++ + } + nSrc += size + } + return +} + +// ReplaceIllFormed returns a transformer that replaces all input bytes that are +// not part of a well-formed UTF-8 code sequence with utf8.RuneError. +func ReplaceIllFormed() Transformer { + return Transformer{&replaceIllFormed{}} +} + +type replaceIllFormed struct{ transform.NopResetter } + +func (t replaceIllFormed) Span(src []byte, atEOF bool) (n int, err error) { + for n < len(src) { + // ASCII fast path. + if src[n] < utf8.RuneSelf { + n++ + continue + } + + r, size := utf8.DecodeRune(src[n:]) + + // Look for a valid non-ASCII rune. + if r != utf8.RuneError || size != 1 { + n += size + continue + } + + // Look for short source data. + if !atEOF && !utf8.FullRune(src[n:]) { + err = transform.ErrShortSrc + break + } + + // We have an invalid rune. + err = transform.ErrEndOfSpan + break + } + return n, err +} + +func (t replaceIllFormed) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + for nSrc < len(src) { + // ASCII fast path. + if r := src[nSrc]; r < utf8.RuneSelf { + if nDst == len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst] = r + nDst++ + nSrc++ + continue + } + + // Look for a valid non-ASCII rune. + if _, size := utf8.DecodeRune(src[nSrc:]); size != 1 { + if size != copy(dst[nDst:], src[nSrc:nSrc+size]) { + err = transform.ErrShortDst + break + } + nDst += size + nSrc += size + continue + } + + // Look for short source data. + if !atEOF && !utf8.FullRune(src[nSrc:]) { + err = transform.ErrShortSrc + break + } + + // We have an invalid rune. + if nDst+3 > len(dst) { + err = transform.ErrShortDst + break + } + dst[nDst+0] = runeErrorString[0] + dst[nDst+1] = runeErrorString[1] + dst[nDst+2] = runeErrorString[2] + nDst += 3 + nSrc++ + } + return nDst, nSrc, err +} diff --git a/vendor/golang.org/x/text/transform/transform.go b/vendor/golang.org/x/text/transform/transform.go new file mode 100644 index 00000000..520b9ada --- /dev/null +++ b/vendor/golang.org/x/text/transform/transform.go @@ -0,0 +1,705 @@ +// Copyright 2013 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. + +// Package transform provides reader and writer wrappers that transform the +// bytes passing through as well as various transformations. Example +// transformations provided by other packages include normalization and +// conversion between character sets. +package transform // import "golang.org/x/text/transform" + +import ( + "bytes" + "errors" + "io" + "unicode/utf8" +) + +var ( + // ErrShortDst means that the destination buffer was too short to + // receive all of the transformed bytes. + ErrShortDst = errors.New("transform: short destination buffer") + + // ErrShortSrc means that the source buffer has insufficient data to + // complete the transformation. + ErrShortSrc = errors.New("transform: short source buffer") + + // ErrEndOfSpan means that the input and output (the transformed input) + // are not identical. + ErrEndOfSpan = errors.New("transform: input and output are not identical") + + // errInconsistentByteCount means that Transform returned success (nil + // error) but also returned nSrc inconsistent with the src argument. + errInconsistentByteCount = errors.New("transform: inconsistent byte count returned") + + // errShortInternal means that an internal buffer is not large enough + // to make progress and the Transform operation must be aborted. + errShortInternal = errors.New("transform: short internal buffer") +) + +// Transformer transforms bytes. +type Transformer interface { + // Transform writes to dst the transformed bytes read from src, and + // returns the number of dst bytes written and src bytes read. The + // atEOF argument tells whether src represents the last bytes of the + // input. + // + // Callers should always process the nDst bytes produced and account + // for the nSrc bytes consumed before considering the error err. + // + // A nil error means that all of the transformed bytes (whether freshly + // transformed from src or left over from previous Transform calls) + // were written to dst. A nil error can be returned regardless of + // whether atEOF is true. If err is nil then nSrc must equal len(src); + // the converse is not necessarily true. + // + // ErrShortDst means that dst was too short to receive all of the + // transformed bytes. ErrShortSrc means that src had insufficient data + // to complete the transformation. If both conditions apply, then + // either error may be returned. Other than the error conditions listed + // here, implementations are free to report other errors that arise. + Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) + + // Reset resets the state and allows a Transformer to be reused. + Reset() +} + +// SpanningTransformer extends the Transformer interface with a Span method +// that determines how much of the input already conforms to the Transformer. +type SpanningTransformer interface { + Transformer + + // Span returns a position in src such that transforming src[:n] results in + // identical output src[:n] for these bytes. It does not necessarily return + // the largest such n. The atEOF argument tells whether src represents the + // last bytes of the input. + // + // Callers should always account for the n bytes consumed before + // considering the error err. + // + // A nil error means that all input bytes are known to be identical to the + // output produced by the Transformer. A nil error can be returned + // regardless of whether atEOF is true. If err is nil, then n must + // equal len(src); the converse is not necessarily true. + // + // ErrEndOfSpan means that the Transformer output may differ from the + // input after n bytes. Note that n may be len(src), meaning that the output + // would contain additional bytes after otherwise identical output. + // ErrShortSrc means that src had insufficient data to determine whether the + // remaining bytes would change. Other than the error conditions listed + // here, implementations are free to report other errors that arise. + // + // Calling Span can modify the Transformer state as a side effect. In + // effect, it does the transformation just as calling Transform would, only + // without copying to a destination buffer and only up to a point it can + // determine the input and output bytes are the same. This is obviously more + // limited than calling Transform, but can be more efficient in terms of + // copying and allocating buffers. Calls to Span and Transform may be + // interleaved. + Span(src []byte, atEOF bool) (n int, err error) +} + +// NopResetter can be embedded by implementations of Transformer to add a nop +// Reset method. +type NopResetter struct{} + +// Reset implements the Reset method of the Transformer interface. +func (NopResetter) Reset() {} + +// Reader wraps another io.Reader by transforming the bytes read. +type Reader struct { + r io.Reader + t Transformer + err error + + // dst[dst0:dst1] contains bytes that have been transformed by t but + // not yet copied out via Read. + dst []byte + dst0, dst1 int + + // src[src0:src1] contains bytes that have been read from r but not + // yet transformed through t. + src []byte + src0, src1 int + + // transformComplete is whether the transformation is complete, + // regardless of whether or not it was successful. + transformComplete bool +} + +const defaultBufSize = 4096 + +// NewReader returns a new Reader that wraps r by transforming the bytes read +// via t. It calls Reset on t. +func NewReader(r io.Reader, t Transformer) *Reader { + t.Reset() + return &Reader{ + r: r, + t: t, + dst: make([]byte, defaultBufSize), + src: make([]byte, defaultBufSize), + } +} + +// Read implements the io.Reader interface. +func (r *Reader) Read(p []byte) (int, error) { + n, err := 0, error(nil) + for { + // Copy out any transformed bytes and return the final error if we are done. + if r.dst0 != r.dst1 { + n = copy(p, r.dst[r.dst0:r.dst1]) + r.dst0 += n + if r.dst0 == r.dst1 && r.transformComplete { + return n, r.err + } + return n, nil + } else if r.transformComplete { + return 0, r.err + } + + // Try to transform some source bytes, or to flush the transformer if we + // are out of source bytes. We do this even if r.r.Read returned an error. + // As the io.Reader documentation says, "process the n > 0 bytes returned + // before considering the error". + if r.src0 != r.src1 || r.err != nil { + r.dst0 = 0 + r.dst1, n, err = r.t.Transform(r.dst, r.src[r.src0:r.src1], r.err == io.EOF) + r.src0 += n + + switch { + case err == nil: + if r.src0 != r.src1 { + r.err = errInconsistentByteCount + } + // The Transform call was successful; we are complete if we + // cannot read more bytes into src. + r.transformComplete = r.err != nil + continue + case err == ErrShortDst && (r.dst1 != 0 || n != 0): + // Make room in dst by copying out, and try again. + continue + case err == ErrShortSrc && r.src1-r.src0 != len(r.src) && r.err == nil: + // Read more bytes into src via the code below, and try again. + default: + r.transformComplete = true + // The reader error (r.err) takes precedence over the + // transformer error (err) unless r.err is nil or io.EOF. + if r.err == nil || r.err == io.EOF { + r.err = err + } + continue + } + } + + // Move any untransformed source bytes to the start of the buffer + // and read more bytes. + if r.src0 != 0 { + r.src0, r.src1 = 0, copy(r.src, r.src[r.src0:r.src1]) + } + n, r.err = r.r.Read(r.src[r.src1:]) + r.src1 += n + } +} + +// TODO: implement ReadByte (and ReadRune??). + +// Writer wraps another io.Writer by transforming the bytes read. +// The user needs to call Close to flush unwritten bytes that may +// be buffered. +type Writer struct { + w io.Writer + t Transformer + dst []byte + + // src[:n] contains bytes that have not yet passed through t. + src []byte + n int +} + +// NewWriter returns a new Writer that wraps w by transforming the bytes written +// via t. It calls Reset on t. +func NewWriter(w io.Writer, t Transformer) *Writer { + t.Reset() + return &Writer{ + w: w, + t: t, + dst: make([]byte, defaultBufSize), + src: make([]byte, defaultBufSize), + } +} + +// Write implements the io.Writer interface. If there are not enough +// bytes available to complete a Transform, the bytes will be buffered +// for the next write. Call Close to convert the remaining bytes. +func (w *Writer) Write(data []byte) (n int, err error) { + src := data + if w.n > 0 { + // Append bytes from data to the last remainder. + // TODO: limit the amount copied on first try. + n = copy(w.src[w.n:], data) + w.n += n + src = w.src[:w.n] + } + for { + nDst, nSrc, err := w.t.Transform(w.dst, src, false) + if _, werr := w.w.Write(w.dst[:nDst]); werr != nil { + return n, werr + } + src = src[nSrc:] + if w.n == 0 { + n += nSrc + } else if len(src) <= n { + // Enough bytes from w.src have been consumed. We make src point + // to data instead to reduce the copying. + w.n = 0 + n -= len(src) + src = data[n:] + if n < len(data) && (err == nil || err == ErrShortSrc) { + continue + } + } + switch err { + case ErrShortDst: + // This error is okay as long as we are making progress. + if nDst > 0 || nSrc > 0 { + continue + } + case ErrShortSrc: + if len(src) < len(w.src) { + m := copy(w.src, src) + // If w.n > 0, bytes from data were already copied to w.src and n + // was already set to the number of bytes consumed. + if w.n == 0 { + n += m + } + w.n = m + err = nil + } else if nDst > 0 || nSrc > 0 { + // Not enough buffer to store the remainder. Keep processing as + // long as there is progress. Without this case, transforms that + // require a lookahead larger than the buffer may result in an + // error. This is not something one may expect to be common in + // practice, but it may occur when buffers are set to small + // sizes during testing. + continue + } + case nil: + if w.n > 0 { + err = errInconsistentByteCount + } + } + return n, err + } +} + +// Close implements the io.Closer interface. +func (w *Writer) Close() error { + src := w.src[:w.n] + for { + nDst, nSrc, err := w.t.Transform(w.dst, src, true) + if _, werr := w.w.Write(w.dst[:nDst]); werr != nil { + return werr + } + if err != ErrShortDst { + return err + } + src = src[nSrc:] + } +} + +type nop struct{ NopResetter } + +func (nop) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + n := copy(dst, src) + if n < len(src) { + err = ErrShortDst + } + return n, n, err +} + +func (nop) Span(src []byte, atEOF bool) (n int, err error) { + return len(src), nil +} + +type discard struct{ NopResetter } + +func (discard) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + return 0, len(src), nil +} + +var ( + // Discard is a Transformer for which all Transform calls succeed + // by consuming all bytes and writing nothing. + Discard Transformer = discard{} + + // Nop is a SpanningTransformer that copies src to dst. + Nop SpanningTransformer = nop{} +) + +// chain is a sequence of links. A chain with N Transformers has N+1 links and +// N+1 buffers. Of those N+1 buffers, the first and last are the src and dst +// buffers given to chain.Transform and the middle N-1 buffers are intermediate +// buffers owned by the chain. The i'th link transforms bytes from the i'th +// buffer chain.link[i].b at read offset chain.link[i].p to the i+1'th buffer +// chain.link[i+1].b at write offset chain.link[i+1].n, for i in [0, N). +type chain struct { + link []link + err error + // errStart is the index at which the error occurred plus 1. Processing + // errStart at this level at the next call to Transform. As long as + // errStart > 0, chain will not consume any more source bytes. + errStart int +} + +func (c *chain) fatalError(errIndex int, err error) { + if i := errIndex + 1; i > c.errStart { + c.errStart = i + c.err = err + } +} + +type link struct { + t Transformer + // b[p:n] holds the bytes to be transformed by t. + b []byte + p int + n int +} + +func (l *link) src() []byte { + return l.b[l.p:l.n] +} + +func (l *link) dst() []byte { + return l.b[l.n:] +} + +// Chain returns a Transformer that applies t in sequence. +func Chain(t ...Transformer) Transformer { + if len(t) == 0 { + return nop{} + } + c := &chain{link: make([]link, len(t)+1)} + for i, tt := range t { + c.link[i].t = tt + } + // Allocate intermediate buffers. + b := make([][defaultBufSize]byte, len(t)-1) + for i := range b { + c.link[i+1].b = b[i][:] + } + return c +} + +// Reset resets the state of Chain. It calls Reset on all the Transformers. +func (c *chain) Reset() { + for i, l := range c.link { + if l.t != nil { + l.t.Reset() + } + c.link[i].p, c.link[i].n = 0, 0 + } +} + +// TODO: make chain use Span (is going to be fun to implement!) + +// Transform applies the transformers of c in sequence. +func (c *chain) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + // Set up src and dst in the chain. + srcL := &c.link[0] + dstL := &c.link[len(c.link)-1] + srcL.b, srcL.p, srcL.n = src, 0, len(src) + dstL.b, dstL.n = dst, 0 + var lastFull, needProgress bool // for detecting progress + + // i is the index of the next Transformer to apply, for i in [low, high]. + // low is the lowest index for which c.link[low] may still produce bytes. + // high is the highest index for which c.link[high] has a Transformer. + // The error returned by Transform determines whether to increase or + // decrease i. We try to completely fill a buffer before converting it. + for low, i, high := c.errStart, c.errStart, len(c.link)-2; low <= i && i <= high; { + in, out := &c.link[i], &c.link[i+1] + nDst, nSrc, err0 := in.t.Transform(out.dst(), in.src(), atEOF && low == i) + out.n += nDst + in.p += nSrc + if i > 0 && in.p == in.n { + in.p, in.n = 0, 0 + } + needProgress, lastFull = lastFull, false + switch err0 { + case ErrShortDst: + // Process the destination buffer next. Return if we are already + // at the high index. + if i == high { + return dstL.n, srcL.p, ErrShortDst + } + if out.n != 0 { + i++ + // If the Transformer at the next index is not able to process any + // source bytes there is nothing that can be done to make progress + // and the bytes will remain unprocessed. lastFull is used to + // detect this and break out of the loop with a fatal error. + lastFull = true + continue + } + // The destination buffer was too small, but is completely empty. + // Return a fatal error as this transformation can never complete. + c.fatalError(i, errShortInternal) + case ErrShortSrc: + if i == 0 { + // Save ErrShortSrc in err. All other errors take precedence. + err = ErrShortSrc + break + } + // Source bytes were depleted before filling up the destination buffer. + // Verify we made some progress, move the remaining bytes to the errStart + // and try to get more source bytes. + if needProgress && nSrc == 0 || in.n-in.p == len(in.b) { + // There were not enough source bytes to proceed while the source + // buffer cannot hold any more bytes. Return a fatal error as this + // transformation can never complete. + c.fatalError(i, errShortInternal) + break + } + // in.b is an internal buffer and we can make progress. + in.p, in.n = 0, copy(in.b, in.src()) + fallthrough + case nil: + // if i == low, we have depleted the bytes at index i or any lower levels. + // In that case we increase low and i. In all other cases we decrease i to + // fetch more bytes before proceeding to the next index. + if i > low { + i-- + continue + } + default: + c.fatalError(i, err0) + } + // Exhausted level low or fatal error: increase low and continue + // to process the bytes accepted so far. + i++ + low = i + } + + // If c.errStart > 0, this means we found a fatal error. We will clear + // all upstream buffers. At this point, no more progress can be made + // downstream, as Transform would have bailed while handling ErrShortDst. + if c.errStart > 0 { + for i := 1; i < c.errStart; i++ { + c.link[i].p, c.link[i].n = 0, 0 + } + err, c.errStart, c.err = c.err, 0, nil + } + return dstL.n, srcL.p, err +} + +// Deprecated: Use runes.Remove instead. +func RemoveFunc(f func(r rune) bool) Transformer { + return removeF(f) +} + +type removeF func(r rune) bool + +func (removeF) Reset() {} + +// Transform implements the Transformer interface. +func (t removeF) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + for r, sz := rune(0), 0; len(src) > 0; src = src[sz:] { + + if r = rune(src[0]); r < utf8.RuneSelf { + sz = 1 + } else { + r, sz = utf8.DecodeRune(src) + + if sz == 1 { + // Invalid rune. + if !atEOF && !utf8.FullRune(src) { + err = ErrShortSrc + break + } + // We replace illegal bytes with RuneError. Not doing so might + // otherwise turn a sequence of invalid UTF-8 into valid UTF-8. + // The resulting byte sequence may subsequently contain runes + // for which t(r) is true that were passed unnoticed. + if !t(r) { + if nDst+3 > len(dst) { + err = ErrShortDst + break + } + nDst += copy(dst[nDst:], "\uFFFD") + } + nSrc++ + continue + } + } + + if !t(r) { + if nDst+sz > len(dst) { + err = ErrShortDst + break + } + nDst += copy(dst[nDst:], src[:sz]) + } + nSrc += sz + } + return +} + +// grow returns a new []byte that is longer than b, and copies the first n bytes +// of b to the start of the new slice. +func grow(b []byte, n int) []byte { + m := len(b) + if m <= 32 { + m = 64 + } else if m <= 256 { + m *= 2 + } else { + m += m >> 1 + } + buf := make([]byte, m) + copy(buf, b[:n]) + return buf +} + +const initialBufSize = 128 + +// String returns a string with the result of converting s[:n] using t, where +// n <= len(s). If err == nil, n will be len(s). It calls Reset on t. +func String(t Transformer, s string) (result string, n int, err error) { + t.Reset() + if s == "" { + // Fast path for the common case for empty input. Results in about a + // 86% reduction of running time for BenchmarkStringLowerEmpty. + if _, _, err := t.Transform(nil, nil, true); err == nil { + return "", 0, nil + } + } + + // Allocate only once. Note that both dst and src escape when passed to + // Transform. + buf := [2 * initialBufSize]byte{} + dst := buf[:initialBufSize:initialBufSize] + src := buf[initialBufSize : 2*initialBufSize] + + // The input string s is transformed in multiple chunks (starting with a + // chunk size of initialBufSize). nDst and nSrc are per-chunk (or + // per-Transform-call) indexes, pDst and pSrc are overall indexes. + nDst, nSrc := 0, 0 + pDst, pSrc := 0, 0 + + // pPrefix is the length of a common prefix: the first pPrefix bytes of the + // result will equal the first pPrefix bytes of s. It is not guaranteed to + // be the largest such value, but if pPrefix, len(result) and len(s) are + // all equal after the final transform (i.e. calling Transform with atEOF + // being true returned nil error) then we don't need to allocate a new + // result string. + pPrefix := 0 + for { + // Invariant: pDst == pPrefix && pSrc == pPrefix. + + n := copy(src, s[pSrc:]) + nDst, nSrc, err = t.Transform(dst, src[:n], pSrc+n == len(s)) + pDst += nDst + pSrc += nSrc + + // TODO: let transformers implement an optional Spanner interface, akin + // to norm's QuickSpan. This would even allow us to avoid any allocation. + if !bytes.Equal(dst[:nDst], src[:nSrc]) { + break + } + pPrefix = pSrc + if err == ErrShortDst { + // A buffer can only be short if a transformer modifies its input. + break + } else if err == ErrShortSrc { + if nSrc == 0 { + // No progress was made. + break + } + // Equal so far and !atEOF, so continue checking. + } else if err != nil || pPrefix == len(s) { + return string(s[:pPrefix]), pPrefix, err + } + } + // Post-condition: pDst == pPrefix + nDst && pSrc == pPrefix + nSrc. + + // We have transformed the first pSrc bytes of the input s to become pDst + // transformed bytes. Those transformed bytes are discontiguous: the first + // pPrefix of them equal s[:pPrefix] and the last nDst of them equal + // dst[:nDst]. We copy them around, into a new dst buffer if necessary, so + // that they become one contiguous slice: dst[:pDst]. + if pPrefix != 0 { + newDst := dst + if pDst > len(newDst) { + newDst = make([]byte, len(s)+nDst-nSrc) + } + copy(newDst[pPrefix:pDst], dst[:nDst]) + copy(newDst[:pPrefix], s[:pPrefix]) + dst = newDst + } + + // Prevent duplicate Transform calls with atEOF being true at the end of + // the input. Also return if we have an unrecoverable error. + if (err == nil && pSrc == len(s)) || + (err != nil && err != ErrShortDst && err != ErrShortSrc) { + return string(dst[:pDst]), pSrc, err + } + + // Transform the remaining input, growing dst and src buffers as necessary. + for { + n := copy(src, s[pSrc:]) + nDst, nSrc, err := t.Transform(dst[pDst:], src[:n], pSrc+n == len(s)) + pDst += nDst + pSrc += nSrc + + // If we got ErrShortDst or ErrShortSrc, do not grow as long as we can + // make progress. This may avoid excessive allocations. + if err == ErrShortDst { + if nDst == 0 { + dst = grow(dst, pDst) + } + } else if err == ErrShortSrc { + if nSrc == 0 { + src = grow(src, 0) + } + } else if err != nil || pSrc == len(s) { + return string(dst[:pDst]), pSrc, err + } + } +} + +// Bytes returns a new byte slice with the result of converting b[:n] using t, +// where n <= len(b). If err == nil, n will be len(b). It calls Reset on t. +func Bytes(t Transformer, b []byte) (result []byte, n int, err error) { + return doAppend(t, 0, make([]byte, len(b)), b) +} + +// Append appends the result of converting src[:n] using t to dst, where +// n <= len(src), If err == nil, n will be len(src). It calls Reset on t. +func Append(t Transformer, dst, src []byte) (result []byte, n int, err error) { + if len(dst) == cap(dst) { + n := len(src) + len(dst) // It is okay for this to be 0. + b := make([]byte, n) + dst = b[:copy(b, dst)] + } + return doAppend(t, len(dst), dst[:cap(dst)], src) +} + +func doAppend(t Transformer, pDst int, dst, src []byte) (result []byte, n int, err error) { + t.Reset() + pSrc := 0 + for { + nDst, nSrc, err := t.Transform(dst[pDst:], src[pSrc:], true) + pDst += nDst + pSrc += nSrc + if err != ErrShortDst { + return dst[:pDst], pSrc, err + } + + // Grow the destination buffer, but do not grow as long as we can make + // progress. This may avoid excessive allocations. + if nDst == 0 { + dst = grow(dst, pDst) + } + } +} |