forked from forgejo/forgejo
Added all required dependencies
This commit is contained in:
Thomas Boerger
parent
78f86abba4
commit
1ebb35b988
660 changed files with 502447 additions and 0 deletions
705
vendor/golang.org/x/text/transform/transform.go
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vendor/golang.org/x/text/transform/transform.go
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// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package transform provides reader and writer wrappers that transform the
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// bytes passing through as well as various transformations. Example
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// transformations provided by other packages include normalization and
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// conversion between character sets.
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package transform // import "golang.org/x/text/transform"
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import (
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"bytes"
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"errors"
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"io"
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"unicode/utf8"
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)
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var (
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// ErrShortDst means that the destination buffer was too short to
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// receive all of the transformed bytes.
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ErrShortDst = errors.New("transform: short destination buffer")
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// ErrShortSrc means that the source buffer has insufficient data to
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// complete the transformation.
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ErrShortSrc = errors.New("transform: short source buffer")
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// ErrEndOfSpan means that the input and output (the transformed input)
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// are not identical.
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ErrEndOfSpan = errors.New("transform: input and output are not identical")
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// errInconsistentByteCount means that Transform returned success (nil
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// error) but also returned nSrc inconsistent with the src argument.
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errInconsistentByteCount = errors.New("transform: inconsistent byte count returned")
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// errShortInternal means that an internal buffer is not large enough
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// to make progress and the Transform operation must be aborted.
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errShortInternal = errors.New("transform: short internal buffer")
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)
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// Transformer transforms bytes.
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type Transformer interface {
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// Transform writes to dst the transformed bytes read from src, and
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// returns the number of dst bytes written and src bytes read. The
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// atEOF argument tells whether src represents the last bytes of the
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// input.
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//
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// Callers should always process the nDst bytes produced and account
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// for the nSrc bytes consumed before considering the error err.
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//
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// A nil error means that all of the transformed bytes (whether freshly
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// transformed from src or left over from previous Transform calls)
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// were written to dst. A nil error can be returned regardless of
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// whether atEOF is true. If err is nil then nSrc must equal len(src);
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// the converse is not necessarily true.
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//
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// ErrShortDst means that dst was too short to receive all of the
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// transformed bytes. ErrShortSrc means that src had insufficient data
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// to complete the transformation. If both conditions apply, then
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// either error may be returned. Other than the error conditions listed
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// here, implementations are free to report other errors that arise.
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Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error)
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// Reset resets the state and allows a Transformer to be reused.
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Reset()
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}
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// SpanningTransformer extends the Transformer interface with a Span method
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// that determines how much of the input already conforms to the Transformer.
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type SpanningTransformer interface {
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Transformer
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// Span returns a position in src such that transforming src[:n] results in
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// identical output src[:n] for these bytes. It does not necessarily return
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// the largest such n. The atEOF argument tells whether src represents the
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// last bytes of the input.
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//
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// Callers should always account for the n bytes consumed before
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// considering the error err.
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//
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// A nil error means that all input bytes are known to be identical to the
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// output produced by the Transformer. A nil error can be be returned
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// regardless of whether atEOF is true. If err is nil, then then n must
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// equal len(src); the converse is not necessarily true.
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//
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// ErrEndOfSpan means that the Transformer output may differ from the
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// input after n bytes. Note that n may be len(src), meaning that the output
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// would contain additional bytes after otherwise identical output.
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// ErrShortSrc means that src had insufficient data to determine whether the
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// remaining bytes would change. Other than the error conditions listed
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// here, implementations are free to report other errors that arise.
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//
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// Calling Span can modify the Transformer state as a side effect. In
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// effect, it does the transformation just as calling Transform would, only
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// without copying to a destination buffer and only up to a point it can
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// determine the input and output bytes are the same. This is obviously more
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// limited than calling Transform, but can be more efficient in terms of
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// copying and allocating buffers. Calls to Span and Transform may be
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// interleaved.
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Span(src []byte, atEOF bool) (n int, err error)
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}
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// NopResetter can be embedded by implementations of Transformer to add a nop
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// Reset method.
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type NopResetter struct{}
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// Reset implements the Reset method of the Transformer interface.
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func (NopResetter) Reset() {}
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// Reader wraps another io.Reader by transforming the bytes read.
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type Reader struct {
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r io.Reader
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t Transformer
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err error
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// dst[dst0:dst1] contains bytes that have been transformed by t but
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// not yet copied out via Read.
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dst []byte
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dst0, dst1 int
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// src[src0:src1] contains bytes that have been read from r but not
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// yet transformed through t.
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src []byte
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src0, src1 int
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// transformComplete is whether the transformation is complete,
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// regardless of whether or not it was successful.
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transformComplete bool
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}
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const defaultBufSize = 4096
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// NewReader returns a new Reader that wraps r by transforming the bytes read
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// via t. It calls Reset on t.
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func NewReader(r io.Reader, t Transformer) *Reader {
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t.Reset()
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return &Reader{
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r: r,
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t: t,
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dst: make([]byte, defaultBufSize),
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src: make([]byte, defaultBufSize),
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}
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}
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// Read implements the io.Reader interface.
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func (r *Reader) Read(p []byte) (int, error) {
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n, err := 0, error(nil)
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for {
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// Copy out any transformed bytes and return the final error if we are done.
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if r.dst0 != r.dst1 {
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n = copy(p, r.dst[r.dst0:r.dst1])
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r.dst0 += n
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if r.dst0 == r.dst1 && r.transformComplete {
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return n, r.err
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}
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return n, nil
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} else if r.transformComplete {
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return 0, r.err
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}
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// Try to transform some source bytes, or to flush the transformer if we
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// are out of source bytes. We do this even if r.r.Read returned an error.
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// As the io.Reader documentation says, "process the n > 0 bytes returned
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// before considering the error".
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if r.src0 != r.src1 || r.err != nil {
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r.dst0 = 0
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r.dst1, n, err = r.t.Transform(r.dst, r.src[r.src0:r.src1], r.err == io.EOF)
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r.src0 += n
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switch {
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case err == nil:
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if r.src0 != r.src1 {
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r.err = errInconsistentByteCount
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}
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// The Transform call was successful; we are complete if we
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// cannot read more bytes into src.
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r.transformComplete = r.err != nil
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continue
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case err == ErrShortDst && (r.dst1 != 0 || n != 0):
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// Make room in dst by copying out, and try again.
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continue
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case err == ErrShortSrc && r.src1-r.src0 != len(r.src) && r.err == nil:
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// Read more bytes into src via the code below, and try again.
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default:
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r.transformComplete = true
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// The reader error (r.err) takes precedence over the
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// transformer error (err) unless r.err is nil or io.EOF.
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if r.err == nil || r.err == io.EOF {
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r.err = err
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}
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continue
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}
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}
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// Move any untransformed source bytes to the start of the buffer
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// and read more bytes.
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if r.src0 != 0 {
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r.src0, r.src1 = 0, copy(r.src, r.src[r.src0:r.src1])
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}
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n, r.err = r.r.Read(r.src[r.src1:])
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r.src1 += n
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}
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}
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// TODO: implement ReadByte (and ReadRune??).
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// Writer wraps another io.Writer by transforming the bytes read.
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// The user needs to call Close to flush unwritten bytes that may
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// be buffered.
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type Writer struct {
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w io.Writer
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t Transformer
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dst []byte
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// src[:n] contains bytes that have not yet passed through t.
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src []byte
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n int
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}
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// NewWriter returns a new Writer that wraps w by transforming the bytes written
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// via t. It calls Reset on t.
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func NewWriter(w io.Writer, t Transformer) *Writer {
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t.Reset()
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return &Writer{
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w: w,
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t: t,
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dst: make([]byte, defaultBufSize),
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src: make([]byte, defaultBufSize),
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}
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}
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// Write implements the io.Writer interface. If there are not enough
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// bytes available to complete a Transform, the bytes will be buffered
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// for the next write. Call Close to convert the remaining bytes.
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func (w *Writer) Write(data []byte) (n int, err error) {
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src := data
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if w.n > 0 {
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// Append bytes from data to the last remainder.
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// TODO: limit the amount copied on first try.
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n = copy(w.src[w.n:], data)
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w.n += n
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src = w.src[:w.n]
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}
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for {
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nDst, nSrc, err := w.t.Transform(w.dst, src, false)
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if _, werr := w.w.Write(w.dst[:nDst]); werr != nil {
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return n, werr
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}
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src = src[nSrc:]
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if w.n == 0 {
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n += nSrc
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} else if len(src) <= n {
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// Enough bytes from w.src have been consumed. We make src point
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// to data instead to reduce the copying.
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w.n = 0
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n -= len(src)
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src = data[n:]
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if n < len(data) && (err == nil || err == ErrShortSrc) {
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continue
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}
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}
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switch err {
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case ErrShortDst:
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// This error is okay as long as we are making progress.
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if nDst > 0 || nSrc > 0 {
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continue
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}
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case ErrShortSrc:
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if len(src) < len(w.src) {
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m := copy(w.src, src)
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// If w.n > 0, bytes from data were already copied to w.src and n
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// was already set to the number of bytes consumed.
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if w.n == 0 {
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n += m
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}
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w.n = m
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err = nil
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} else if nDst > 0 || nSrc > 0 {
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// Not enough buffer to store the remainder. Keep processing as
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// long as there is progress. Without this case, transforms that
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// require a lookahead larger than the buffer may result in an
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// error. This is not something one may expect to be common in
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// practice, but it may occur when buffers are set to small
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// sizes during testing.
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continue
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}
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case nil:
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if w.n > 0 {
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err = errInconsistentByteCount
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}
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}
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return n, err
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}
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}
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// Close implements the io.Closer interface.
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func (w *Writer) Close() error {
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src := w.src[:w.n]
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for {
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nDst, nSrc, err := w.t.Transform(w.dst, src, true)
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if _, werr := w.w.Write(w.dst[:nDst]); werr != nil {
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return werr
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}
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if err != ErrShortDst {
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return err
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}
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src = src[nSrc:]
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}
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}
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type nop struct{ NopResetter }
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func (nop) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
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n := copy(dst, src)
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if n < len(src) {
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err = ErrShortDst
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}
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return n, n, err
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}
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func (nop) Span(src []byte, atEOF bool) (n int, err error) {
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return len(src), nil
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}
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type discard struct{ NopResetter }
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func (discard) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
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return 0, len(src), nil
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}
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var (
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// Discard is a Transformer for which all Transform calls succeed
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// by consuming all bytes and writing nothing.
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Discard Transformer = discard{}
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// Nop is a SpanningTransformer that copies src to dst.
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Nop SpanningTransformer = nop{}
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)
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// chain is a sequence of links. A chain with N Transformers has N+1 links and
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// N+1 buffers. Of those N+1 buffers, the first and last are the src and dst
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// buffers given to chain.Transform and the middle N-1 buffers are intermediate
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// buffers owned by the chain. The i'th link transforms bytes from the i'th
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// buffer chain.link[i].b at read offset chain.link[i].p to the i+1'th buffer
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// chain.link[i+1].b at write offset chain.link[i+1].n, for i in [0, N).
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type chain struct {
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link []link
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err error
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// errStart is the index at which the error occurred plus 1. Processing
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// errStart at this level at the next call to Transform. As long as
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// errStart > 0, chain will not consume any more source bytes.
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errStart int
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}
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func (c *chain) fatalError(errIndex int, err error) {
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if i := errIndex + 1; i > c.errStart {
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c.errStart = i
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c.err = err
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}
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}
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type link struct {
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t Transformer
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// b[p:n] holds the bytes to be transformed by t.
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b []byte
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p int
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n int
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}
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func (l *link) src() []byte {
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return l.b[l.p:l.n]
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}
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func (l *link) dst() []byte {
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return l.b[l.n:]
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}
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// Chain returns a Transformer that applies t in sequence.
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func Chain(t ...Transformer) Transformer {
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if len(t) == 0 {
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return nop{}
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}
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c := &chain{link: make([]link, len(t)+1)}
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for i, tt := range t {
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c.link[i].t = tt
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}
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// Allocate intermediate buffers.
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b := make([][defaultBufSize]byte, len(t)-1)
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for i := range b {
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c.link[i+1].b = b[i][:]
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}
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return c
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}
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// Reset resets the state of Chain. It calls Reset on all the Transformers.
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func (c *chain) Reset() {
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for i, l := range c.link {
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if l.t != nil {
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l.t.Reset()
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}
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c.link[i].p, c.link[i].n = 0, 0
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}
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}
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// TODO: make chain use Span (is going to be fun to implement!)
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// Transform applies the transformers of c in sequence.
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func (c *chain) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
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// Set up src and dst in the chain.
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srcL := &c.link[0]
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dstL := &c.link[len(c.link)-1]
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srcL.b, srcL.p, srcL.n = src, 0, len(src)
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dstL.b, dstL.n = dst, 0
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var lastFull, needProgress bool // for detecting progress
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// i is the index of the next Transformer to apply, for i in [low, high].
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// low is the lowest index for which c.link[low] may still produce bytes.
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// high is the highest index for which c.link[high] has a Transformer.
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// The error returned by Transform determines whether to increase or
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// decrease i. We try to completely fill a buffer before converting it.
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for low, i, high := c.errStart, c.errStart, len(c.link)-2; low <= i && i <= high; {
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in, out := &c.link[i], &c.link[i+1]
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nDst, nSrc, err0 := in.t.Transform(out.dst(), in.src(), atEOF && low == i)
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out.n += nDst
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in.p += nSrc
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if i > 0 && in.p == in.n {
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in.p, in.n = 0, 0
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}
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needProgress, lastFull = lastFull, false
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switch err0 {
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case ErrShortDst:
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// Process the destination buffer next. Return if we are already
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// at the high index.
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if i == high {
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return dstL.n, srcL.p, ErrShortDst
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}
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if out.n != 0 {
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i++
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// If the Transformer at the next index is not able to process any
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// source bytes there is nothing that can be done to make progress
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// and the bytes will remain unprocessed. lastFull is used to
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// detect this and break out of the loop with a fatal error.
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lastFull = true
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continue
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}
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||||
// The destination buffer was too small, but is completely empty.
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||||
// Return a fatal error as this transformation can never complete.
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||||
c.fatalError(i, errShortInternal)
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case ErrShortSrc:
|
||||
if i == 0 {
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// Save ErrShortSrc in err. All other errors take precedence.
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err = ErrShortSrc
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||||
break
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||||
}
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// Source bytes were depleted before filling up the destination buffer.
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// Verify we made some progress, move the remaining bytes to the errStart
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// and try to get more source bytes.
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||||
if needProgress && nSrc == 0 || in.n-in.p == len(in.b) {
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||||
// There were not enough source bytes to proceed while the source
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// buffer cannot hold any more bytes. Return a fatal error as this
|
||||
// transformation can never complete.
|
||||
c.fatalError(i, errShortInternal)
|
||||
break
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||||
}
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||||
// in.b is an internal buffer and we can make progress.
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||||
in.p, in.n = 0, copy(in.b, in.src())
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fallthrough
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||||
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)
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue