Godeps, vendor: convert dependency management to trash (#3198)

This commit converts the dependency management from Godeps to the vendor
folder, also switching the tool from godep to trash. Since the upstream tool
lacks a few features proposed via a few PRs, until those PRs are merged in
(if), use github.com/karalabe/trash.

You can update dependencies via trash --update.

All dependencies have been updated to their latest version.

Parts of the build system are reworked to drop old notions of Godeps and
invocation of the go vet command so that it doesn't run against the vendor
folder, as that will just blow up during vetting.

The conversion drops OpenCL (and hence GPU mining support) from ethash and our
codebase. The short reasoning is that there's noone to maintain and having
opencl libs in our deps messes up builds as go install ./... tries to build
them, failing with unsatisfied link errors for the C OpenCL deps.

golang.org/x/net/context is not vendored in. We expect it to be fetched by the
user (i.e. using go get). To keep ci.go builds reproducible the package is
"vendored" in build/_vendor.

1 files changed, 375 insertions, 0 deletions

diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/table/writer.go b/vendor/github.com/syndtr/goleveldb/leveldb/table/writer.go
new file mode 100644
index 000000000..b96b271d8
--- /dev/null
+++ b/vendor/github.com/syndtr/goleveldb/leveldb/table/writer.go
@@ -0,0 +1,375 @@
+// 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 table
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/golang/snappy"
+
+	"github.com/syndtr/goleveldb/leveldb/comparer"
+	"github.com/syndtr/goleveldb/leveldb/filter"
+	"github.com/syndtr/goleveldb/leveldb/opt"
+	"github.com/syndtr/goleveldb/leveldb/util"
+)
+
+func sharedPrefixLen(a, b []byte) int {
+	i, n := 0, len(a)
+	if n > len(b) {
+		n = len(b)
+	}
+	for i < n && a[i] == b[i] {
+		i++
+	}
+	return i
+}
+
+type blockWriter struct {
+	restartInterval int
+	buf             util.Buffer
+	nEntries        int
+	prevKey         []byte
+	restarts        []uint32
+	scratch         []byte
+}
+
+func (w *blockWriter) append(key, value []byte) {
+	nShared := 0
+	if w.nEntries%w.restartInterval == 0 {
+		w.restarts = append(w.restarts, uint32(w.buf.Len()))
+	} else {
+		nShared = sharedPrefixLen(w.prevKey, key)
+	}
+	n := binary.PutUvarint(w.scratch[0:], uint64(nShared))
+	n += binary.PutUvarint(w.scratch[n:], uint64(len(key)-nShared))
+	n += binary.PutUvarint(w.scratch[n:], uint64(len(value)))
+	w.buf.Write(w.scratch[:n])
+	w.buf.Write(key[nShared:])
+	w.buf.Write(value)
+	w.prevKey = append(w.prevKey[:0], key...)
+	w.nEntries++
+}
+
+func (w *blockWriter) finish() {
+	// Write restarts entry.
+	if w.nEntries == 0 {
+		// Must have at least one restart entry.
+		w.restarts = append(w.restarts, 0)
+	}
+	w.restarts = append(w.restarts, uint32(len(w.restarts)))
+	for _, x := range w.restarts {
+		buf4 := w.buf.Alloc(4)
+		binary.LittleEndian.PutUint32(buf4, x)
+	}
+}
+
+func (w *blockWriter) reset() {
+	w.buf.Reset()
+	w.nEntries = 0
+	w.restarts = w.restarts[:0]
+}
+
+func (w *blockWriter) bytesLen() int {
+	restartsLen := len(w.restarts)
+	if restartsLen == 0 {
+		restartsLen = 1
+	}
+	return w.buf.Len() + 4*restartsLen + 4
+}
+
+type filterWriter struct {
+	generator filter.FilterGenerator
+	buf       util.Buffer
+	nKeys     int
+	offsets   []uint32
+}
+
+func (w *filterWriter) add(key []byte) {
+	if w.generator == nil {
+		return
+	}
+	w.generator.Add(key)
+	w.nKeys++
+}
+
+func (w *filterWriter) flush(offset uint64) {
+	if w.generator == nil {
+		return
+	}
+	for x := int(offset / filterBase); x > len(w.offsets); {
+		w.generate()
+	}
+}
+
+func (w *filterWriter) finish() {
+	if w.generator == nil {
+		return
+	}
+	// Generate last keys.
+
+	if w.nKeys > 0 {
+		w.generate()
+	}
+	w.offsets = append(w.offsets, uint32(w.buf.Len()))
+	for _, x := range w.offsets {
+		buf4 := w.buf.Alloc(4)
+		binary.LittleEndian.PutUint32(buf4, x)
+	}
+	w.buf.WriteByte(filterBaseLg)
+}
+
+func (w *filterWriter) generate() {
+	// Record offset.
+	w.offsets = append(w.offsets, uint32(w.buf.Len()))
+	// Generate filters.
+	if w.nKeys > 0 {
+		w.generator.Generate(&w.buf)
+		w.nKeys = 0
+	}
+}
+
+// Writer is a table writer.
+type Writer struct {
+	writer io.Writer
+	err    error
+	// Options
+	cmp         comparer.Comparer
+	filter      filter.Filter
+	compression opt.Compression
+	blockSize   int
+
+	dataBlock   blockWriter
+	indexBlock  blockWriter
+	filterBlock filterWriter
+	pendingBH   blockHandle
+	offset      uint64
+	nEntries    int
+	// Scratch allocated enough for 5 uvarint. Block writer should not use
+	// first 20-bytes since it will be used to encode block handle, which
+	// then passed to the block writer itself.
+	scratch            [50]byte
+	comparerScratch    []byte
+	compressionScratch []byte
+}
+
+func (w *Writer) writeBlock(buf *util.Buffer, compression opt.Compression) (bh blockHandle, err error) {
+	// Compress the buffer if necessary.
+	var b []byte
+	if compression == opt.SnappyCompression {
+		// Allocate scratch enough for compression and block trailer.
+		if n := snappy.MaxEncodedLen(buf.Len()) + blockTrailerLen; len(w.compressionScratch) < n {
+			w.compressionScratch = make([]byte, n)
+		}
+		compressed := snappy.Encode(w.compressionScratch, buf.Bytes())
+		n := len(compressed)
+		b = compressed[:n+blockTrailerLen]
+		b[n] = blockTypeSnappyCompression
+	} else {
+		tmp := buf.Alloc(blockTrailerLen)
+		tmp[0] = blockTypeNoCompression
+		b = buf.Bytes()
+	}
+
+	// Calculate the checksum.
+	n := len(b) - 4
+	checksum := util.NewCRC(b[:n]).Value()
+	binary.LittleEndian.PutUint32(b[n:], checksum)
+
+	// Write the buffer to the file.
+	_, err = w.writer.Write(b)
+	if err != nil {
+		return
+	}
+	bh = blockHandle{w.offset, uint64(len(b) - blockTrailerLen)}
+	w.offset += uint64(len(b))
+	return
+}
+
+func (w *Writer) flushPendingBH(key []byte) {
+	if w.pendingBH.length == 0 {
+		return
+	}
+	var separator []byte
+	if len(key) == 0 {
+		separator = w.cmp.Successor(w.comparerScratch[:0], w.dataBlock.prevKey)
+	} else {
+		separator = w.cmp.Separator(w.comparerScratch[:0], w.dataBlock.prevKey, key)
+	}
+	if separator == nil {
+		separator = w.dataBlock.prevKey
+	} else {
+		w.comparerScratch = separator
+	}
+	n := encodeBlockHandle(w.scratch[:20], w.pendingBH)
+	// Append the block handle to the index block.
+	w.indexBlock.append(separator, w.scratch[:n])
+	// Reset prev key of the data block.
+	w.dataBlock.prevKey = w.dataBlock.prevKey[:0]
+	// Clear pending block handle.
+	w.pendingBH = blockHandle{}
+}
+
+func (w *Writer) finishBlock() error {
+	w.dataBlock.finish()
+	bh, err := w.writeBlock(&w.dataBlock.buf, w.compression)
+	if err != nil {
+		return err
+	}
+	w.pendingBH = bh
+	// Reset the data block.
+	w.dataBlock.reset()
+	// Flush the filter block.
+	w.filterBlock.flush(w.offset)
+	return nil
+}
+
+// Append appends key/value pair to the table. The keys passed must
+// be in increasing order.
+//
+// It is safe to modify the contents of the arguments after Append returns.
+func (w *Writer) Append(key, value []byte) error {
+	if w.err != nil {
+		return w.err
+	}
+	if w.nEntries > 0 && w.cmp.Compare(w.dataBlock.prevKey, key) >= 0 {
+		w.err = fmt.Errorf("leveldb/table: Writer: keys are not in increasing order: %q, %q", w.dataBlock.prevKey, key)
+		return w.err
+	}
+
+	w.flushPendingBH(key)
+	// Append key/value pair to the data block.
+	w.dataBlock.append(key, value)
+	// Add key to the filter block.
+	w.filterBlock.add(key)
+
+	// Finish the data block if block size target reached.
+	if w.dataBlock.bytesLen() >= w.blockSize {
+		if err := w.finishBlock(); err != nil {
+			w.err = err
+			return w.err
+		}
+	}
+	w.nEntries++
+	return nil
+}
+
+// BlocksLen returns number of blocks written so far.
+func (w *Writer) BlocksLen() int {
+	n := w.indexBlock.nEntries
+	if w.pendingBH.length > 0 {
+		// Includes the pending block.
+		n++
+	}
+	return n
+}
+
+// EntriesLen returns number of entries added so far.
+func (w *Writer) EntriesLen() int {
+	return w.nEntries
+}
+
+// BytesLen returns number of bytes written so far.
+func (w *Writer) BytesLen() int {
+	return int(w.offset)
+}
+
+// Close will finalize the table. Calling Append is not possible
+// after Close, but calling BlocksLen, EntriesLen and BytesLen
+// is still possible.
+func (w *Writer) Close() error {
+	if w.err != nil {
+		return w.err
+	}
+
+	// Write the last data block. Or empty data block if there
+	// aren't any data blocks at all.
+	if w.dataBlock.nEntries > 0 || w.nEntries == 0 {
+		if err := w.finishBlock(); err != nil {
+			w.err = err
+			return w.err
+		}
+	}
+	w.flushPendingBH(nil)
+
+	// Write the filter block.
+	var filterBH blockHandle
+	w.filterBlock.finish()
+	if buf := &w.filterBlock.buf; buf.Len() > 0 {
+		filterBH, w.err = w.writeBlock(buf, opt.NoCompression)
+		if w.err != nil {
+			return w.err
+		}
+	}
+
+	// Write the metaindex block.
+	if filterBH.length > 0 {
+		key := []byte("filter." + w.filter.Name())
+		n := encodeBlockHandle(w.scratch[:20], filterBH)
+		w.dataBlock.append(key, w.scratch[:n])
+	}
+	w.dataBlock.finish()
+	metaindexBH, err := w.writeBlock(&w.dataBlock.buf, w.compression)
+	if err != nil {
+		w.err = err
+		return w.err
+	}
+
+	// Write the index block.
+	w.indexBlock.finish()
+	indexBH, err := w.writeBlock(&w.indexBlock.buf, w.compression)
+	if err != nil {
+		w.err = err
+		return w.err
+	}
+
+	// Write the table footer.
+	footer := w.scratch[:footerLen]
+	for i := range footer {
+		footer[i] = 0
+	}
+	n := encodeBlockHandle(footer, metaindexBH)
+	encodeBlockHandle(footer[n:], indexBH)
+	copy(footer[footerLen-len(magic):], magic)
+	if _, err := w.writer.Write(footer); err != nil {
+		w.err = err
+		return w.err
+	}
+	w.offset += footerLen
+
+	w.err = errors.New("leveldb/table: writer is closed")
+	return nil
+}
+
+// NewWriter creates a new initialized table writer for the file.
+//
+// Table writer is not safe for concurrent use.
+func NewWriter(f io.Writer, o *opt.Options) *Writer {
+	w := &Writer{
+		writer:          f,
+		cmp:             o.GetComparer(),
+		filter:          o.GetFilter(),
+		compression:     o.GetCompression(),
+		blockSize:       o.GetBlockSize(),
+		comparerScratch: make([]byte, 0),
+	}
+	// data block
+	w.dataBlock.restartInterval = o.GetBlockRestartInterval()
+	// The first 20-bytes are used for encoding block handle.
+	w.dataBlock.scratch = w.scratch[20:]
+	// index block
+	w.indexBlock.restartInterval = 1
+	w.indexBlock.scratch = w.scratch[20:]
+	// filter block
+	if w.filter != nil {
+		w.filterBlock.generator = w.filter.NewGenerator()
+		w.filterBlock.flush(0)
+	}
+	return w
+}