Imported Upstream version 1.4upstream/1.4

1 files changed, 0 insertions, 307 deletions

diff --git a/src/pkg/index/suffixarray/suffixarray.go b/src/pkg/index/suffixarray/suffixarray.go
deleted file mode 100644
index c59ae6eef..000000000
--- a/src/pkg/index/suffixarray/suffixarray.go
+++ /dev/null
@@ -1,307 +0,0 @@
-// Copyright 2010 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 suffixarray implements substring search in logarithmic time using
-// an in-memory suffix array.
-//
-// Example use:
-//
-//	// create index for some data
-//	index := suffixarray.New(data)
-//
-//	// lookup byte slice s
-//	offsets1 := index.Lookup(s, -1) // the list of all indices where s occurs in data
-//	offsets2 := index.Lookup(s, 3)  // the list of at most 3 indices where s occurs in data
-//
-package suffixarray
-
-import (
-	"bytes"
-	"encoding/binary"
-	"io"
-	"regexp"
-	"sort"
-)
-
-// Index implements a suffix array for fast substring search.
-type Index struct {
-	data []byte
-	sa   []int // suffix array for data; len(sa) == len(data)
-}
-
-// New creates a new Index for data.
-// Index creation time is O(N*log(N)) for N = len(data).
-func New(data []byte) *Index {
-	return &Index{data, qsufsort(data)}
-}
-
-// writeInt writes an int x to w using buf to buffer the write.
-func writeInt(w io.Writer, buf []byte, x int) error {
-	binary.PutVarint(buf, int64(x))
-	_, err := w.Write(buf[0:binary.MaxVarintLen64])
-	return err
-}
-
-// readInt reads an int x from r using buf to buffer the read and returns x.
-func readInt(r io.Reader, buf []byte) (int, error) {
-	_, err := io.ReadFull(r, buf[0:binary.MaxVarintLen64]) // ok to continue with error
-	x, _ := binary.Varint(buf)
-	return int(x), err
-}
-
-// writeSlice writes data[:n] to w and returns n.
-// It uses buf to buffer the write.
-func writeSlice(w io.Writer, buf []byte, data []int) (n int, err error) {
-	// encode as many elements as fit into buf
-	p := binary.MaxVarintLen64
-	for ; n < len(data) && p+binary.MaxVarintLen64 <= len(buf); n++ {
-		p += binary.PutUvarint(buf[p:], uint64(data[n]))
-	}
-
-	// update buffer size
-	binary.PutVarint(buf, int64(p))
-
-	// write buffer
-	_, err = w.Write(buf[0:p])
-	return
-}
-
-// readSlice reads data[:n] from r and returns n.
-// It uses buf to buffer the read.
-func readSlice(r io.Reader, buf []byte, data []int) (n int, err error) {
-	// read buffer size
-	var size int
-	size, err = readInt(r, buf)
-	if err != nil {
-		return
-	}
-
-	// read buffer w/o the size
-	if _, err = io.ReadFull(r, buf[binary.MaxVarintLen64:size]); err != nil {
-		return
-	}
-
-	// decode as many elements as present in buf
-	for p := binary.MaxVarintLen64; p < size; n++ {
-		x, w := binary.Uvarint(buf[p:])
-		data[n] = int(x)
-		p += w
-	}
-
-	return
-}
-
-const bufSize = 16 << 10 // reasonable for BenchmarkSaveRestore
-
-// Read reads the index from r into x; x must not be nil.
-func (x *Index) Read(r io.Reader) error {
-	// buffer for all reads
-	buf := make([]byte, bufSize)
-
-	// read length
-	n, err := readInt(r, buf)
-	if err != nil {
-		return err
-	}
-
-	// allocate space
-	if 2*n < cap(x.data) || cap(x.data) < n {
-		// new data is significantly smaller or larger then
-		// existing buffers - allocate new ones
-		x.data = make([]byte, n)
-		x.sa = make([]int, n)
-	} else {
-		// re-use existing buffers
-		x.data = x.data[0:n]
-		x.sa = x.sa[0:n]
-	}
-
-	// read data
-	if _, err := io.ReadFull(r, x.data); err != nil {
-		return err
-	}
-
-	// read index
-	for sa := x.sa; len(sa) > 0; {
-		n, err := readSlice(r, buf, sa)
-		if err != nil {
-			return err
-		}
-		sa = sa[n:]
-	}
-	return nil
-}
-
-// Write writes the index x to w.
-func (x *Index) Write(w io.Writer) error {
-	// buffer for all writes
-	buf := make([]byte, bufSize)
-
-	// write length
-	if err := writeInt(w, buf, len(x.data)); err != nil {
-		return err
-	}
-
-	// write data
-	if _, err := w.Write(x.data); err != nil {
-		return err
-	}
-
-	// write index
-	for sa := x.sa; len(sa) > 0; {
-		n, err := writeSlice(w, buf, sa)
-		if err != nil {
-			return err
-		}
-		sa = sa[n:]
-	}
-	return nil
-}
-
-// Bytes returns the data over which the index was created.
-// It must not be modified.
-//
-func (x *Index) Bytes() []byte {
-	return x.data
-}
-
-func (x *Index) at(i int) []byte {
-	return x.data[x.sa[i]:]
-}
-
-// lookupAll returns a slice into the matching region of the index.
-// The runtime is O(log(N)*len(s)).
-func (x *Index) lookupAll(s []byte) []int {
-	// find matching suffix index range [i:j]
-	// find the first index where s would be the prefix
-	i := sort.Search(len(x.sa), func(i int) bool { return bytes.Compare(x.at(i), s) >= 0 })
-	// starting at i, find the first index at which s is not a prefix
-	j := i + sort.Search(len(x.sa)-i, func(j int) bool { return !bytes.HasPrefix(x.at(j+i), s) })
-	return x.sa[i:j]
-}
-
-// Lookup returns an unsorted list of at most n indices where the byte string s
-// occurs in the indexed data. If n < 0, all occurrences are returned.
-// The result is nil if s is empty, s is not found, or n == 0.
-// Lookup time is O(log(N)*len(s) + len(result)) where N is the
-// size of the indexed data.
-//
-func (x *Index) Lookup(s []byte, n int) (result []int) {
-	if len(s) > 0 && n != 0 {
-		matches := x.lookupAll(s)
-		if n < 0 || len(matches) < n {
-			n = len(matches)
-		}
-		// 0 <= n <= len(matches)
-		if n > 0 {
-			result = make([]int, n)
-			copy(result, matches)
-		}
-	}
-	return
-}
-
-// FindAllIndex returns a sorted list of non-overlapping matches of the
-// regular expression r, where a match is a pair of indices specifying
-// the matched slice of x.Bytes(). If n < 0, all matches are returned
-// in successive order. Otherwise, at most n matches are returned and
-// they may not be successive. The result is nil if there are no matches,
-// or if n == 0.
-//
-func (x *Index) FindAllIndex(r *regexp.Regexp, n int) (result [][]int) {
-	// a non-empty literal prefix is used to determine possible
-	// match start indices with Lookup
-	prefix, complete := r.LiteralPrefix()
-	lit := []byte(prefix)
-
-	// worst-case scenario: no literal prefix
-	if prefix == "" {
-		return r.FindAllIndex(x.data, n)
-	}
-
-	// if regexp is a literal just use Lookup and convert its
-	// result into match pairs
-	if complete {
-		// Lookup returns indices that may belong to overlapping matches.
-		// After eliminating them, we may end up with fewer than n matches.
-		// If we don't have enough at the end, redo the search with an
-		// increased value n1, but only if Lookup returned all the requested
-		// indices in the first place (if it returned fewer than that then
-		// there cannot be more).
-		for n1 := n; ; n1 += 2 * (n - len(result)) /* overflow ok */ {
-			indices := x.Lookup(lit, n1)
-			if len(indices) == 0 {
-				return
-			}
-			sort.Ints(indices)
-			pairs := make([]int, 2*len(indices))
-			result = make([][]int, len(indices))
-			count := 0
-			prev := 0
-			for _, i := range indices {
-				if count == n {
-					break
-				}
-				// ignore indices leading to overlapping matches
-				if prev <= i {
-					j := 2 * count
-					pairs[j+0] = i
-					pairs[j+1] = i + len(lit)
-					result[count] = pairs[j : j+2]
-					count++
-					prev = i + len(lit)
-				}
-			}
-			result = result[0:count]
-			if len(result) >= n || len(indices) != n1 {
-				// found all matches or there's no chance to find more
-				// (n and n1 can be negative)
-				break
-			}
-		}
-		if len(result) == 0 {
-			result = nil
-		}
-		return
-	}
-
-	// regexp has a non-empty literal prefix; Lookup(lit) computes
-	// the indices of possible complete matches; use these as starting
-	// points for anchored searches
-	// (regexp "^" matches beginning of input, not beginning of line)
-	r = regexp.MustCompile("^" + r.String()) // compiles because r compiled
-
-	// same comment about Lookup applies here as in the loop above
-	for n1 := n; ; n1 += 2 * (n - len(result)) /* overflow ok */ {
-		indices := x.Lookup(lit, n1)
-		if len(indices) == 0 {
-			return
-		}
-		sort.Ints(indices)
-		result = result[0:0]
-		prev := 0
-		for _, i := range indices {
-			if len(result) == n {
-				break
-			}
-			m := r.FindIndex(x.data[i:]) // anchored search - will not run off
-			// ignore indices leading to overlapping matches
-			if m != nil && prev <= i {
-				m[0] = i // correct m
-				m[1] += i
-				result = append(result, m)
-				prev = m[1]
-			}
-		}
-		if len(result) >= n || len(indices) != n1 {
-			// found all matches or there's no chance to find more
-			// (n and n1 can be negative)
-			break
-		}
-	}
-	if len(result) == 0 {
-		result = nil
-	}
-	return
-}