diff options
Diffstat (limited to 'Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util')
6 files changed, 805 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/buffer.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/buffer.go new file mode 100644 index 000000000..21de24255 --- /dev/null +++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/buffer.go @@ -0,0 +1,293 @@ +// Copyright 2009 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 util + +// This a copy of Go std bytes.Buffer with some modification +// and some features stripped. + +import ( + "bytes" + "io" +) + +// A Buffer is a variable-sized buffer of bytes with Read and Write methods. +// The zero value for Buffer is an empty buffer ready to use. +type Buffer struct { + buf []byte // contents are the bytes buf[off : len(buf)] + off int // read at &buf[off], write at &buf[len(buf)] + bootstrap [64]byte // memory to hold first slice; helps small buffers (Printf) avoid allocation. +} + +// Bytes returns a slice of the contents of the unread portion of the buffer; +// len(b.Bytes()) == b.Len(). If the caller changes the contents of the +// returned slice, the contents of the buffer will change provided there +// are no intervening method calls on the Buffer. +func (b *Buffer) Bytes() []byte { return b.buf[b.off:] } + +// String returns the contents of the unread portion of the buffer +// as a string. If the Buffer is a nil pointer, it returns "<nil>". +func (b *Buffer) String() string { + if b == nil { + // Special case, useful in debugging. + return "<nil>" + } + return string(b.buf[b.off:]) +} + +// Len returns the number of bytes of the unread portion of the buffer; +// b.Len() == len(b.Bytes()). +func (b *Buffer) Len() int { return len(b.buf) - b.off } + +// Truncate discards all but the first n unread bytes from the buffer. +// It panics if n is negative or greater than the length of the buffer. +func (b *Buffer) Truncate(n int) { + switch { + case n < 0 || n > b.Len(): + panic("leveldb/util.Buffer: truncation out of range") + case n == 0: + // Reuse buffer space. + b.off = 0 + } + b.buf = b.buf[0 : b.off+n] +} + +// Reset resets the buffer so it has no content. +// b.Reset() is the same as b.Truncate(0). +func (b *Buffer) Reset() { b.Truncate(0) } + +// grow grows the buffer to guarantee space for n more bytes. +// It returns the index where bytes should be written. +// If the buffer can't grow it will panic with bytes.ErrTooLarge. +func (b *Buffer) grow(n int) int { + m := b.Len() + // If buffer is empty, reset to recover space. + if m == 0 && b.off != 0 { + b.Truncate(0) + } + if len(b.buf)+n > cap(b.buf) { + var buf []byte + if b.buf == nil && n <= len(b.bootstrap) { + buf = b.bootstrap[0:] + } else if m+n <= cap(b.buf)/2 { + // We can slide things down instead of allocating a new + // slice. We only need m+n <= cap(b.buf) to slide, but + // we instead let capacity get twice as large so we + // don't spend all our time copying. + copy(b.buf[:], b.buf[b.off:]) + buf = b.buf[:m] + } else { + // not enough space anywhere + buf = makeSlice(2*cap(b.buf) + n) + copy(buf, b.buf[b.off:]) + } + b.buf = buf + b.off = 0 + } + b.buf = b.buf[0 : b.off+m+n] + return b.off + m +} + +// Alloc allocs n bytes of slice from the buffer, growing the buffer as +// needed. If n is negative, Alloc will panic. +// If the buffer can't grow it will panic with bytes.ErrTooLarge. +func (b *Buffer) Alloc(n int) []byte { + if n < 0 { + panic("leveldb/util.Buffer.Alloc: negative count") + } + m := b.grow(n) + return b.buf[m:] +} + +// Grow grows the buffer's capacity, if necessary, to guarantee space for +// another n bytes. After Grow(n), at least n bytes can be written to the +// buffer without another allocation. +// If n is negative, Grow will panic. +// If the buffer can't grow it will panic with bytes.ErrTooLarge. +func (b *Buffer) Grow(n int) { + if n < 0 { + panic("leveldb/util.Buffer.Grow: negative count") + } + m := b.grow(n) + b.buf = b.buf[0:m] +} + +// Write appends the contents of p to the buffer, growing the buffer as +// needed. The return value n is the length of p; err is always nil. If the +// buffer becomes too large, Write will panic with bytes.ErrTooLarge. +func (b *Buffer) Write(p []byte) (n int, err error) { + m := b.grow(len(p)) + return copy(b.buf[m:], p), nil +} + +// MinRead is the minimum slice size passed to a Read call by +// Buffer.ReadFrom. As long as the Buffer has at least MinRead bytes beyond +// what is required to hold the contents of r, ReadFrom will not grow the +// underlying buffer. +const MinRead = 512 + +// ReadFrom reads data from r until EOF and appends it to the buffer, growing +// the buffer as needed. The return value n is the number of bytes read. Any +// error except io.EOF encountered during the read is also returned. If the +// buffer becomes too large, ReadFrom will panic with bytes.ErrTooLarge. +func (b *Buffer) ReadFrom(r io.Reader) (n int64, err error) { + // If buffer is empty, reset to recover space. + if b.off >= len(b.buf) { + b.Truncate(0) + } + for { + if free := cap(b.buf) - len(b.buf); free < MinRead { + // not enough space at end + newBuf := b.buf + if b.off+free < MinRead { + // not enough space using beginning of buffer; + // double buffer capacity + newBuf = makeSlice(2*cap(b.buf) + MinRead) + } + copy(newBuf, b.buf[b.off:]) + b.buf = newBuf[:len(b.buf)-b.off] + b.off = 0 + } + m, e := r.Read(b.buf[len(b.buf):cap(b.buf)]) + b.buf = b.buf[0 : len(b.buf)+m] + n += int64(m) + if e == io.EOF { + break + } + if e != nil { + return n, e + } + } + return n, nil // err is EOF, so return nil explicitly +} + +// makeSlice allocates a slice of size n. If the allocation fails, it panics +// with bytes.ErrTooLarge. +func makeSlice(n int) []byte { + // If the make fails, give a known error. + defer func() { + if recover() != nil { + panic(bytes.ErrTooLarge) + } + }() + return make([]byte, n) +} + +// WriteTo writes data to w until the buffer is drained or an error occurs. +// The return value n is the number of bytes written; it always fits into an +// int, but it is int64 to match the io.WriterTo interface. Any error +// encountered during the write is also returned. +func (b *Buffer) WriteTo(w io.Writer) (n int64, err error) { + if b.off < len(b.buf) { + nBytes := b.Len() + m, e := w.Write(b.buf[b.off:]) + if m > nBytes { + panic("leveldb/util.Buffer.WriteTo: invalid Write count") + } + b.off += m + n = int64(m) + if e != nil { + return n, e + } + // all bytes should have been written, by definition of + // Write method in io.Writer + if m != nBytes { + return n, io.ErrShortWrite + } + } + // Buffer is now empty; reset. + b.Truncate(0) + return +} + +// WriteByte appends the byte c to the buffer, growing the buffer as needed. +// The returned error is always nil, but is included to match bufio.Writer's +// WriteByte. If the buffer becomes too large, WriteByte will panic with +// bytes.ErrTooLarge. +func (b *Buffer) WriteByte(c byte) error { + m := b.grow(1) + b.buf[m] = c + return nil +} + +// Read reads the next len(p) bytes from the buffer or until the buffer +// is drained. The return value n is the number of bytes read. If the +// buffer has no data to return, err is io.EOF (unless len(p) is zero); +// otherwise it is nil. +func (b *Buffer) Read(p []byte) (n int, err error) { + if b.off >= len(b.buf) { + // Buffer is empty, reset to recover space. + b.Truncate(0) + if len(p) == 0 { + return + } + return 0, io.EOF + } + n = copy(p, b.buf[b.off:]) + b.off += n + return +} + +// Next returns a slice containing the next n bytes from the buffer, +// advancing the buffer as if the bytes had been returned by Read. +// If there are fewer than n bytes in the buffer, Next returns the entire buffer. +// The slice is only valid until the next call to a read or write method. +func (b *Buffer) Next(n int) []byte { + m := b.Len() + if n > m { + n = m + } + data := b.buf[b.off : b.off+n] + b.off += n + return data +} + +// ReadByte reads and returns the next byte from the buffer. +// If no byte is available, it returns error io.EOF. +func (b *Buffer) ReadByte() (c byte, err error) { + if b.off >= len(b.buf) { + // Buffer is empty, reset to recover space. + b.Truncate(0) + return 0, io.EOF + } + c = b.buf[b.off] + b.off++ + return c, nil +} + +// ReadBytes reads until the first occurrence of delim in the input, +// returning a slice containing the data up to and including the delimiter. +// If ReadBytes encounters an error before finding a delimiter, +// it returns the data read before the error and the error itself (often io.EOF). +// ReadBytes returns err != nil if and only if the returned data does not end in +// delim. +func (b *Buffer) ReadBytes(delim byte) (line []byte, err error) { + slice, err := b.readSlice(delim) + // return a copy of slice. The buffer's backing array may + // be overwritten by later calls. + line = append(line, slice...) + return +} + +// readSlice is like ReadBytes but returns a reference to internal buffer data. +func (b *Buffer) readSlice(delim byte) (line []byte, err error) { + i := bytes.IndexByte(b.buf[b.off:], delim) + end := b.off + i + 1 + if i < 0 { + end = len(b.buf) + err = io.EOF + } + line = b.buf[b.off:end] + b.off = end + return line, err +} + +// NewBuffer creates and initializes a new Buffer using buf as its initial +// contents. It is intended to prepare a Buffer to read existing data. It +// can also be used to size the internal buffer for writing. To do that, +// buf should have the desired capacity but a length of zero. +// +// In most cases, new(Buffer) (or just declaring a Buffer variable) is +// sufficient to initialize a Buffer. +func NewBuffer(buf []byte) *Buffer { return &Buffer{buf: buf} } diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/buffer_test.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/buffer_test.go new file mode 100644 index 000000000..87d96739c --- /dev/null +++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/buffer_test.go @@ -0,0 +1,369 @@ +// Copyright 2009 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 util + +import ( + "bytes" + "io" + "math/rand" + "runtime" + "testing" +) + +const N = 10000 // make this bigger for a larger (and slower) test +var data string // test data for write tests +var testBytes []byte // test data; same as data but as a slice. + +func init() { + testBytes = make([]byte, N) + for i := 0; i < N; i++ { + testBytes[i] = 'a' + byte(i%26) + } + data = string(testBytes) +} + +// Verify that contents of buf match the string s. +func check(t *testing.T, testname string, buf *Buffer, s string) { + bytes := buf.Bytes() + str := buf.String() + if buf.Len() != len(bytes) { + t.Errorf("%s: buf.Len() == %d, len(buf.Bytes()) == %d", testname, buf.Len(), len(bytes)) + } + + if buf.Len() != len(str) { + t.Errorf("%s: buf.Len() == %d, len(buf.String()) == %d", testname, buf.Len(), len(str)) + } + + if buf.Len() != len(s) { + t.Errorf("%s: buf.Len() == %d, len(s) == %d", testname, buf.Len(), len(s)) + } + + if string(bytes) != s { + t.Errorf("%s: string(buf.Bytes()) == %q, s == %q", testname, string(bytes), s) + } +} + +// Fill buf through n writes of byte slice fub. +// The initial contents of buf corresponds to the string s; +// the result is the final contents of buf returned as a string. +func fillBytes(t *testing.T, testname string, buf *Buffer, s string, n int, fub []byte) string { + check(t, testname+" (fill 1)", buf, s) + for ; n > 0; n-- { + m, err := buf.Write(fub) + if m != len(fub) { + t.Errorf(testname+" (fill 2): m == %d, expected %d", m, len(fub)) + } + if err != nil { + t.Errorf(testname+" (fill 3): err should always be nil, found err == %s", err) + } + s += string(fub) + check(t, testname+" (fill 4)", buf, s) + } + return s +} + +func TestNewBuffer(t *testing.T) { + buf := NewBuffer(testBytes) + check(t, "NewBuffer", buf, data) +} + +// Empty buf through repeated reads into fub. +// The initial contents of buf corresponds to the string s. +func empty(t *testing.T, testname string, buf *Buffer, s string, fub []byte) { + check(t, testname+" (empty 1)", buf, s) + + for { + n, err := buf.Read(fub) + if n == 0 { + break + } + if err != nil { + t.Errorf(testname+" (empty 2): err should always be nil, found err == %s", err) + } + s = s[n:] + check(t, testname+" (empty 3)", buf, s) + } + + check(t, testname+" (empty 4)", buf, "") +} + +func TestBasicOperations(t *testing.T) { + var buf Buffer + + for i := 0; i < 5; i++ { + check(t, "TestBasicOperations (1)", &buf, "") + + buf.Reset() + check(t, "TestBasicOperations (2)", &buf, "") + + buf.Truncate(0) + check(t, "TestBasicOperations (3)", &buf, "") + + n, err := buf.Write([]byte(data[0:1])) + if n != 1 { + t.Errorf("wrote 1 byte, but n == %d", n) + } + if err != nil { + t.Errorf("err should always be nil, but err == %s", err) + } + check(t, "TestBasicOperations (4)", &buf, "a") + + buf.WriteByte(data[1]) + check(t, "TestBasicOperations (5)", &buf, "ab") + + n, err = buf.Write([]byte(data[2:26])) + if n != 24 { + t.Errorf("wrote 25 bytes, but n == %d", n) + } + check(t, "TestBasicOperations (6)", &buf, string(data[0:26])) + + buf.Truncate(26) + check(t, "TestBasicOperations (7)", &buf, string(data[0:26])) + + buf.Truncate(20) + check(t, "TestBasicOperations (8)", &buf, string(data[0:20])) + + empty(t, "TestBasicOperations (9)", &buf, string(data[0:20]), make([]byte, 5)) + empty(t, "TestBasicOperations (10)", &buf, "", make([]byte, 100)) + + buf.WriteByte(data[1]) + c, err := buf.ReadByte() + if err != nil { + t.Error("ReadByte unexpected eof") + } + if c != data[1] { + t.Errorf("ReadByte wrong value c=%v", c) + } + c, err = buf.ReadByte() + if err == nil { + t.Error("ReadByte unexpected not eof") + } + } +} + +func TestLargeByteWrites(t *testing.T) { + var buf Buffer + limit := 30 + if testing.Short() { + limit = 9 + } + for i := 3; i < limit; i += 3 { + s := fillBytes(t, "TestLargeWrites (1)", &buf, "", 5, testBytes) + empty(t, "TestLargeByteWrites (2)", &buf, s, make([]byte, len(data)/i)) + } + check(t, "TestLargeByteWrites (3)", &buf, "") +} + +func TestLargeByteReads(t *testing.T) { + var buf Buffer + for i := 3; i < 30; i += 3 { + s := fillBytes(t, "TestLargeReads (1)", &buf, "", 5, testBytes[0:len(testBytes)/i]) + empty(t, "TestLargeReads (2)", &buf, s, make([]byte, len(data))) + } + check(t, "TestLargeByteReads (3)", &buf, "") +} + +func TestMixedReadsAndWrites(t *testing.T) { + var buf Buffer + s := "" + for i := 0; i < 50; i++ { + wlen := rand.Intn(len(data)) + s = fillBytes(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, testBytes[0:wlen]) + rlen := rand.Intn(len(data)) + fub := make([]byte, rlen) + n, _ := buf.Read(fub) + s = s[n:] + } + empty(t, "TestMixedReadsAndWrites (2)", &buf, s, make([]byte, buf.Len())) +} + +func TestNil(t *testing.T) { + var b *Buffer + if b.String() != "<nil>" { + t.Errorf("expected <nil>; got %q", b.String()) + } +} + +func TestReadFrom(t *testing.T) { + var buf Buffer + for i := 3; i < 30; i += 3 { + s := fillBytes(t, "TestReadFrom (1)", &buf, "", 5, testBytes[0:len(testBytes)/i]) + var b Buffer + b.ReadFrom(&buf) + empty(t, "TestReadFrom (2)", &b, s, make([]byte, len(data))) + } +} + +func TestWriteTo(t *testing.T) { + var buf Buffer + for i := 3; i < 30; i += 3 { + s := fillBytes(t, "TestWriteTo (1)", &buf, "", 5, testBytes[0:len(testBytes)/i]) + var b Buffer + buf.WriteTo(&b) + empty(t, "TestWriteTo (2)", &b, s, make([]byte, len(data))) + } +} + +func TestNext(t *testing.T) { + b := []byte{0, 1, 2, 3, 4} + tmp := make([]byte, 5) + for i := 0; i <= 5; i++ { + for j := i; j <= 5; j++ { + for k := 0; k <= 6; k++ { + // 0 <= i <= j <= 5; 0 <= k <= 6 + // Check that if we start with a buffer + // of length j at offset i and ask for + // Next(k), we get the right bytes. + buf := NewBuffer(b[0:j]) + n, _ := buf.Read(tmp[0:i]) + if n != i { + t.Fatalf("Read %d returned %d", i, n) + } + bb := buf.Next(k) + want := k + if want > j-i { + want = j - i + } + if len(bb) != want { + t.Fatalf("in %d,%d: len(Next(%d)) == %d", i, j, k, len(bb)) + } + for l, v := range bb { + if v != byte(l+i) { + t.Fatalf("in %d,%d: Next(%d)[%d] = %d, want %d", i, j, k, l, v, l+i) + } + } + } + } + } +} + +var readBytesTests = []struct { + buffer string + delim byte + expected []string + err error +}{ + {"", 0, []string{""}, io.EOF}, + {"a\x00", 0, []string{"a\x00"}, nil}, + {"abbbaaaba", 'b', []string{"ab", "b", "b", "aaab"}, nil}, + {"hello\x01world", 1, []string{"hello\x01"}, nil}, + {"foo\nbar", 0, []string{"foo\nbar"}, io.EOF}, + {"alpha\nbeta\ngamma\n", '\n', []string{"alpha\n", "beta\n", "gamma\n"}, nil}, + {"alpha\nbeta\ngamma", '\n', []string{"alpha\n", "beta\n", "gamma"}, io.EOF}, +} + +func TestReadBytes(t *testing.T) { + for _, test := range readBytesTests { + buf := NewBuffer([]byte(test.buffer)) + var err error + for _, expected := range test.expected { + var bytes []byte + bytes, err = buf.ReadBytes(test.delim) + if string(bytes) != expected { + t.Errorf("expected %q, got %q", expected, bytes) + } + if err != nil { + break + } + } + if err != test.err { + t.Errorf("expected error %v, got %v", test.err, err) + } + } +} + +func TestGrow(t *testing.T) { + x := []byte{'x'} + y := []byte{'y'} + tmp := make([]byte, 72) + for _, startLen := range []int{0, 100, 1000, 10000, 100000} { + xBytes := bytes.Repeat(x, startLen) + for _, growLen := range []int{0, 100, 1000, 10000, 100000} { + buf := NewBuffer(xBytes) + // If we read, this affects buf.off, which is good to test. + readBytes, _ := buf.Read(tmp) + buf.Grow(growLen) + yBytes := bytes.Repeat(y, growLen) + // Check no allocation occurs in write, as long as we're single-threaded. + var m1, m2 runtime.MemStats + runtime.ReadMemStats(&m1) + buf.Write(yBytes) + runtime.ReadMemStats(&m2) + if runtime.GOMAXPROCS(-1) == 1 && m1.Mallocs != m2.Mallocs { + t.Errorf("allocation occurred during write") + } + // Check that buffer has correct data. + if !bytes.Equal(buf.Bytes()[0:startLen-readBytes], xBytes[readBytes:]) { + t.Errorf("bad initial data at %d %d", startLen, growLen) + } + if !bytes.Equal(buf.Bytes()[startLen-readBytes:startLen-readBytes+growLen], yBytes) { + t.Errorf("bad written data at %d %d", startLen, growLen) + } + } + } +} + +// Was a bug: used to give EOF reading empty slice at EOF. +func TestReadEmptyAtEOF(t *testing.T) { + b := new(Buffer) + slice := make([]byte, 0) + n, err := b.Read(slice) + if err != nil { + t.Errorf("read error: %v", err) + } + if n != 0 { + t.Errorf("wrong count; got %d want 0", n) + } +} + +// Tests that we occasionally compact. Issue 5154. +func TestBufferGrowth(t *testing.T) { + var b Buffer + buf := make([]byte, 1024) + b.Write(buf[0:1]) + var cap0 int + for i := 0; i < 5<<10; i++ { + b.Write(buf) + b.Read(buf) + if i == 0 { + cap0 = cap(b.buf) + } + } + cap1 := cap(b.buf) + // (*Buffer).grow allows for 2x capacity slop before sliding, + // so set our error threshold at 3x. + if cap1 > cap0*3 { + t.Errorf("buffer cap = %d; too big (grew from %d)", cap1, cap0) + } +} + +// From Issue 5154. +func BenchmarkBufferNotEmptyWriteRead(b *testing.B) { + buf := make([]byte, 1024) + for i := 0; i < b.N; i++ { + var b Buffer + b.Write(buf[0:1]) + for i := 0; i < 5<<10; i++ { + b.Write(buf) + b.Read(buf) + } + } +} + +// Check that we don't compact too often. From Issue 5154. +func BenchmarkBufferFullSmallReads(b *testing.B) { + buf := make([]byte, 1024) + for i := 0; i < b.N; i++ { + var b Buffer + b.Write(buf) + for b.Len()+20 < cap(b.buf) { + b.Write(buf[:10]) + } + for i := 0; i < 5<<10; i++ { + b.Read(buf[:1]) + b.Write(buf[:1]) + } + } +} diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/crc32.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/crc32.go new file mode 100644 index 000000000..631c9d610 --- /dev/null +++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/crc32.go @@ -0,0 +1,30 @@ +// Copyright 2011 The LevelDB-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 util + +import ( + "hash/crc32" +) + +var table = crc32.MakeTable(crc32.Castagnoli) + +// CRC is a CRC-32 checksum computed using Castagnoli's polynomial. +type CRC uint32 + +// NewCRC creates a new crc based on the given bytes. +func NewCRC(b []byte) CRC { + return CRC(0).Update(b) +} + +// Update updates the crc with the given bytes. +func (c CRC) Update(b []byte) CRC { + return CRC(crc32.Update(uint32(c), table, b)) +} + +// Value returns a masked crc. +func (c CRC) Value() uint32 { + return uint32(c>>15|c<<17) + 0xa282ead8 +} diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go new file mode 100644 index 000000000..54903660f --- /dev/null +++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go @@ -0,0 +1,48 @@ +// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com> +// All rights reserved. +// +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +package util + +import ( + "bytes" + "encoding/binary" +) + +// Hash return hash of the given data. +func Hash(data []byte, seed uint32) uint32 { + // Similar to murmur hash + var m uint32 = 0xc6a4a793 + var r uint32 = 24 + h := seed ^ (uint32(len(data)) * m) + + buf := bytes.NewBuffer(data) + for buf.Len() >= 4 { + var w uint32 + binary.Read(buf, binary.LittleEndian, &w) + h += w + h *= m + h ^= (h >> 16) + } + + rest := buf.Bytes() + switch len(rest) { + default: + panic("not reached") + case 3: + h += uint32(rest[2]) << 16 + fallthrough + case 2: + h += uint32(rest[1]) << 8 + fallthrough + case 1: + h += uint32(rest[0]) + h *= m + h ^= (h >> r) + case 0: + } + + return h +} diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/range.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/range.go new file mode 100644 index 000000000..da0583123 --- /dev/null +++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/range.go @@ -0,0 +1,16 @@ +// Copyright (c) 2014, Suryandaru Triandana <syndtr@gmail.com> +// All rights reserved. +// +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +package util + +// Range is a key range. +type Range struct { + // Start of the key range, include in the range. + Start []byte + + // Limit of the key range, not include in the range. + Limit []byte +} diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/util.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/util.go new file mode 100644 index 000000000..229c7d41f --- /dev/null +++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/util.go @@ -0,0 +1,49 @@ +// Copyright (c) 2013, Suryandaru Triandana <syndtr@gmail.com> +// All rights reserved. +// +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Package util provides utilities used throughout leveldb. +package util + +import ( + "errors" +) + +var ( + ErrNotFound = errors.New("leveldb: not found") +) + +// Releaser is the interface that wraps the basic Release method. +type Releaser interface { + // Release releases associated resources. Release should always success + // and can be called multipe times without causing error. + Release() +} + +// ReleaseSetter is the interface that wraps the basic SetReleaser method. +type ReleaseSetter interface { + // SetReleaser associates the given releaser to the resources. The + // releaser will be called once coresponding resources released. + // Calling SetReleaser with nil will clear the releaser. + SetReleaser(releaser Releaser) +} + +// BasicReleaser provides basic implementation of Releaser and ReleaseSetter. +type BasicReleaser struct { + releaser Releaser +} + +// Release implements Releaser.Release. +func (r *BasicReleaser) Release() { + if r.releaser != nil { + r.releaser.Release() + r.releaser = nil + } +} + +// SetReleaser implements ReleaseSetter.SetReleaser. +func (r *BasicReleaser) SetReleaser(releaser Releaser) { + r.releaser = releaser +} |