influxdb/tsdb/engine/tsm1/reader.go

1209 lines
28 KiB
Go

package tsm1
import (
"bytes"
"encoding/binary"
"fmt"
"io"
"math"
"os"
"sort"
"sync"
)
type TSMReader struct {
mu sync.RWMutex
// accessor provides access and decoding of blocks for the reader
accessor blockAccessor
// index is the index of all blocks.
index TSMIndex
// tombstoner ensures tombstoned keys are not available by the index.
tombstoner *Tombstoner
// size is the size of the file on disk.
size int64
// lastModified is the last time this file was modified on disk
lastModified int64
}
// BlockIterator allows iterating over each block in a TSM file in order. It provides
// raw access to the block bytes without decoding them.
type BlockIterator struct {
r *TSMReader
// i is the current key index
i int
// n is the total number of keys
n int
key string
entries []*IndexEntry
err error
}
func (b *BlockIterator) PeekNext() string {
if len(b.entries) > 1 {
return b.key
} else if b.n-b.i > 1 {
key := b.r.KeyAt(b.i + 1)
return key
}
return ""
}
func (b *BlockIterator) Next() bool {
if b.n-b.i == 0 && len(b.entries) == 0 {
return false
}
if len(b.entries) > 0 {
b.entries = b.entries[1:]
if len(b.entries) > 0 {
return true
}
}
if b.n-b.i > 0 {
b.key, b.entries = b.r.Key(b.i)
b.i++
return true
}
return false
}
func (b *BlockIterator) Read() (string, int64, int64, []byte, error) {
if b.err != nil {
return "", 0, 0, nil, b.err
}
buf, err := b.r.readBytes(b.entries[0], nil)
if err != nil {
return "", 0, 0, nil, err
}
return b.key, b.entries[0].MinTime, b.entries[0].MaxTime, buf, err
}
// blockAccessor abstracts a method of accessing blocks from a
// TSM file.
type blockAccessor interface {
init() (TSMIndex, error)
read(key string, timestamp int64) ([]Value, error)
readAll(key string) ([]Value, error)
readBlock(entry *IndexEntry, values []Value) ([]Value, error)
readFloatBlock(entry *IndexEntry, values []FloatValue) ([]FloatValue, error)
readIntegerBlock(entry *IndexEntry, values []IntegerValue) ([]IntegerValue, error)
readStringBlock(entry *IndexEntry, values []StringValue) ([]StringValue, error)
readBooleanBlock(entry *IndexEntry, values []BooleanValue) ([]BooleanValue, error)
readBytes(entry *IndexEntry, buf []byte) ([]byte, error)
path() string
close() error
}
type TSMReaderOptions struct {
// Reader is used to create file IO based reader.
Reader io.ReadSeeker
// MMAPFile is used to create an MMAP based reader.
MMAPFile *os.File
}
func NewTSMReader(r io.ReadSeeker) (*TSMReader, error) {
return NewTSMReaderWithOptions(
TSMReaderOptions{
Reader: r,
})
}
func NewTSMReaderWithOptions(opt TSMReaderOptions) (*TSMReader, error) {
t := &TSMReader{}
if opt.Reader != nil {
// Seek to the end of the file to determine the size
size, err := opt.Reader.Seek(0, os.SEEK_END)
if err != nil {
return nil, err
}
t.size = size
if f, ok := opt.Reader.(*os.File); ok {
stat, err := f.Stat()
if err != nil {
return nil, err
}
t.lastModified = stat.ModTime().UnixNano()
}
t.accessor = &fileAccessor{
r: opt.Reader,
}
} else if opt.MMAPFile != nil {
stat, err := opt.MMAPFile.Stat()
if err != nil {
return nil, err
}
t.size = stat.Size()
t.lastModified = stat.ModTime().UnixNano()
t.accessor = &mmapAccessor{
f: opt.MMAPFile,
}
} else {
panic("invalid options: need Reader or MMAPFile")
}
index, err := t.accessor.init()
if err != nil {
return nil, err
}
t.index = index
t.tombstoner = &Tombstoner{Path: t.Path()}
if err := t.applyTombstones(); err != nil {
return nil, err
}
return t, nil
}
func (t *TSMReader) applyTombstones() error {
// Read any tombstone entries if the exist
tombstones, err := t.tombstoner.ReadAll()
if err != nil {
return fmt.Errorf("init: read tombstones: %v", err)
}
// Update our index
t.index.Delete(tombstones)
return nil
}
func (t *TSMReader) Path() string {
t.mu.Lock()
defer t.mu.Unlock()
return t.accessor.path()
}
func (t *TSMReader) Keys() []string {
return t.index.Keys()
}
func (t *TSMReader) Key(index int) (string, []*IndexEntry) {
return t.index.Key(index)
}
func (t *TSMReader) KeyAt(idx int) string {
return t.index.KeyAt(idx)
}
func (t *TSMReader) ReadAt(entry *IndexEntry, vals []Value) ([]Value, error) {
t.mu.RLock()
defer t.mu.RUnlock()
return t.accessor.readBlock(entry, vals)
}
func (t *TSMReader) ReadFloatBlockAt(entry *IndexEntry, vals []FloatValue) ([]FloatValue, error) {
t.mu.RLock()
defer t.mu.RUnlock()
return t.accessor.readFloatBlock(entry, vals)
}
func (t *TSMReader) ReadIntegerBlockAt(entry *IndexEntry, vals []IntegerValue) ([]IntegerValue, error) {
t.mu.RLock()
defer t.mu.RUnlock()
return t.accessor.readIntegerBlock(entry, vals)
}
func (t *TSMReader) ReadStringBlockAt(entry *IndexEntry, vals []StringValue) ([]StringValue, error) {
t.mu.RLock()
defer t.mu.RUnlock()
return t.accessor.readStringBlock(entry, vals)
}
func (t *TSMReader) ReadBooleanBlockAt(entry *IndexEntry, vals []BooleanValue) ([]BooleanValue, error) {
t.mu.RLock()
defer t.mu.RUnlock()
return t.accessor.readBooleanBlock(entry, vals)
}
func (t *TSMReader) Read(key string, timestamp int64) ([]Value, error) {
t.mu.RLock()
defer t.mu.RUnlock()
return t.accessor.read(key, timestamp)
}
// ReadAll returns all values for a key in all blocks.
func (t *TSMReader) ReadAll(key string) ([]Value, error) {
t.mu.Lock()
defer t.mu.Unlock()
return t.accessor.readAll(key)
}
func (t *TSMReader) readBytes(e *IndexEntry, b []byte) ([]byte, error) {
t.mu.RLock()
defer t.mu.RUnlock()
return t.accessor.readBytes(e, b)
}
func (t *TSMReader) Type(key string) (byte, error) {
return t.index.Type(key)
}
func (t *TSMReader) Close() error {
t.mu.Lock()
defer t.mu.Unlock()
return t.accessor.close()
}
// Remove removes any underlying files stored on disk for this reader.
func (t *TSMReader) Remove() error {
t.mu.Lock()
defer t.mu.Unlock()
path := t.accessor.path()
if path != "" {
os.RemoveAll(path)
}
if err := t.tombstoner.Delete(); err != nil {
return err
}
return nil
}
func (t *TSMReader) Contains(key string) bool {
return t.index.Contains(key)
}
// ContainsValue returns true if key and time might exists in this file. This function could
// return true even though the actual point does not exists. For example, the key may
// exists in this file, but not have point exactly at time t.
func (t *TSMReader) ContainsValue(key string, ts int64) bool {
return t.index.ContainsValue(key, ts)
}
func (t *TSMReader) Delete(keys []string) error {
if err := t.tombstoner.Add(keys); err != nil {
return err
}
t.index.Delete(keys)
return nil
}
// TimeRange returns the min and max time across all keys in the file.
func (t *TSMReader) TimeRange() (int64, int64) {
return t.index.TimeRange()
}
// KeyRange returns the min and max key across all keys in the file.
func (t *TSMReader) KeyRange() (string, string) {
return t.index.KeyRange()
}
func (t *TSMReader) KeyCount() int {
return t.index.KeyCount()
}
func (t *TSMReader) Entries(key string) []*IndexEntry {
return t.index.Entries(key)
}
func (t *TSMReader) IndexSize() uint32 {
return t.index.Size()
}
func (t *TSMReader) Size() uint32 {
t.mu.RLock()
defer t.mu.RUnlock()
return uint32(t.size)
}
func (t *TSMReader) LastModified() int64 {
t.mu.RLock()
defer t.mu.RUnlock()
return t.lastModified
}
// HasTombstones return true if there are any tombstone entries recorded.
func (t *TSMReader) HasTombstones() bool {
t.mu.RLock()
defer t.mu.RUnlock()
return t.tombstoner.HasTombstones()
}
// TombstoneFiles returns any tombstone files associated with this TSM file.
func (t *TSMReader) TombstoneFiles() []FileStat {
t.mu.RLock()
defer t.mu.RUnlock()
return t.tombstoner.TombstoneFiles()
}
func (t *TSMReader) Stats() FileStat {
minTime, maxTime := t.index.TimeRange()
minKey, maxKey := t.index.KeyRange()
return FileStat{
Path: t.Path(),
Size: t.Size(),
LastModified: t.LastModified(),
MinTime: minTime,
MaxTime: maxTime,
MinKey: minKey,
MaxKey: maxKey,
HasTombstone: t.tombstoner.HasTombstones(),
}
}
func (t *TSMReader) BlockIterator() *BlockIterator {
return &BlockIterator{
r: t,
n: t.index.KeyCount(),
}
}
// indirectIndex is a TSMIndex that uses a raw byte slice representation of an index. This
// implementation can be used for indexes that may be MMAPed into memory.
type indirectIndex struct {
mu sync.RWMutex
// indirectIndex works a follows. Assuming we have an index structure in memory as
// the diagram below:
//
// ┌────────────────────────────────────────────────────────────────────┐
// │ Index │
// ├─┬──────────────────────┬──┬───────────────────────┬───┬────────────┘
// │0│ │62│ │145│
// ├─┴───────┬─────────┬────┼──┴──────┬─────────┬──────┼───┴─────┬──────┐
// │Key 1 Len│ Key │... │Key 2 Len│ Key 2 │ ... │ Key 3 │ ... │
// │ 2 bytes │ N bytes │ │ 2 bytes │ N bytes │ │ 2 bytes │ │
// └─────────┴─────────┴────┴─────────┴─────────┴──────┴─────────┴──────┘
// We would build an `offsets` slices where each element pointers to the byte location
// for the first key in the index slice.
// ┌────────────────────────────────────────────────────────────────────┐
// │ Offsets │
// ├────┬────┬────┬─────────────────────────────────────────────────────┘
// │ 0 │ 62 │145 │
// └────┴────┴────┘
// Using this offset slice we can find `Key 2` by doing a binary search
// over the offsets slice. Instead of comparing the value in the offsets
// (e.g. `62`), we use that as an index into the underlying index to
// retrieve the key at postion `62` and perform our comparisons with that.
// When we have identified the correct position in the index for a given
// key, we could perform another binary search or a linear scan. This
// should be fast as well since each index entry is 28 bytes and all
// contiguous in memory. The current implementation uses a linear scan since the
// number of block entries is expected to be < 100 per key.
// b is the underlying index byte slice. This could be a copy on the heap or an MMAP
// slice reference
b []byte
// offsets contains the positions in b for each key. It points to the 2 byte length of
// key.
offsets []int32
// minKey, maxKey are the minium and maximum (lexicographically sorted) contained in the
// file
minKey, maxKey string
// minTime, maxTime are the minimum and maximum times contained in the file across all
// series.
minTime, maxTime int64
}
func NewIndirectIndex() TSMIndex {
return &indirectIndex{}
}
// Add records a new block entry for a key in the index.
func (d *indirectIndex) Add(key string, blockType byte, minTime, maxTime int64, offset int64, size uint32) {
panic("unsupported operation")
}
func (d *indirectIndex) Write(w io.Writer) error {
panic("unsupported operation")
}
// search returns the index of i in offsets for where key is located. If key is not
// in the index, len(index) is returned.
func (d *indirectIndex) search(key []byte) int {
// We use a binary search across our indirect offsets (pointers to all the keys
// in the index slice).
i := sort.Search(len(d.offsets), func(i int) bool {
// i is the position in offsets we are at so get offset it points to
offset := d.offsets[i]
// It's pointing to the start of the key which is a 2 byte length
keyLen := int32(binary.BigEndian.Uint16(d.b[offset : offset+2]))
// See if it matches
return bytes.Compare(d.b[offset+2:offset+2+keyLen], key) >= 0
})
// See if we might have found the right index
if i < len(d.offsets) {
ofs := d.offsets[i]
_, k, err := readKey(d.b[ofs:])
if err != nil {
panic(fmt.Sprintf("error reading key: %v", err))
}
// The search may have returned an i == 0 which could indicated that the value
// searched should be inserted at postion 0. Make sure the key in the index
// matches the search value.
if !bytes.Equal(key, k) {
return len(d.b)
}
return int(ofs)
}
// The key is not in the index. i is the index where it would be inserted so return
// a value outside our offset range.
return len(d.b)
}
// Entries returns all index entries for a key.
func (d *indirectIndex) Entries(key string) []*IndexEntry {
d.mu.RLock()
defer d.mu.RUnlock()
kb := []byte(key)
ofs := d.search(kb)
if ofs < len(d.b) {
n, k, err := readKey(d.b[ofs:])
if err != nil {
panic(fmt.Sprintf("error reading key: %v", err))
}
// The search may have returned an i == 0 which could indicated that the value
// searched should be inserted at postion 0. Make sure the key in the index
// matches the search value.
if !bytes.Equal(kb, k) {
return nil
}
// Read and return all the entries
ofs += n
_, entries, err := readEntries(d.b[ofs:])
if err != nil {
panic(fmt.Sprintf("error reading entries: %v", err))
}
return entries.entries
}
// The key is not in the index. i is the index where it would be inserted.
return nil
}
// Entry returns the index entry for the specified key and timestamp. If no entry
// matches the key an timestamp, nil is returned.
func (d *indirectIndex) Entry(key string, timestamp int64) *IndexEntry {
entries := d.Entries(key)
for _, entry := range entries {
if entry.Contains(timestamp) {
return entry
}
}
return nil
}
func (d *indirectIndex) Keys() []string {
d.mu.RLock()
defer d.mu.RUnlock()
var keys []string
for _, offset := range d.offsets {
_, key, _ := readKey(d.b[offset:])
keys = append(keys, string(key))
}
return keys
}
func (d *indirectIndex) Key(idx int) (string, []*IndexEntry) {
d.mu.RLock()
defer d.mu.RUnlock()
if idx < 0 || idx >= len(d.offsets) {
return "", nil
}
n, key, _ := readKey(d.b[d.offsets[idx]:])
_, entries, _ := readEntries(d.b[int(d.offsets[idx])+n:])
return string(key), entries.entries
}
func (d *indirectIndex) KeyAt(idx int) string {
d.mu.RLock()
defer d.mu.RUnlock()
if idx < 0 || idx >= len(d.offsets) {
return ""
}
_, key, _ := readKey(d.b[d.offsets[idx]:])
return string(key)
}
func (d *indirectIndex) KeyCount() int {
d.mu.RLock()
defer d.mu.RUnlock()
return len(d.offsets)
}
func (d *indirectIndex) Delete(keys []string) {
if len(keys) == 0 {
return
}
d.mu.Lock()
defer d.mu.Unlock()
lookup := map[string]struct{}{}
for _, k := range keys {
lookup[k] = struct{}{}
}
var offsets []int32
for _, offset := range d.offsets {
_, indexKey, _ := readKey(d.b[offset:])
if _, ok := lookup[string(indexKey)]; ok {
continue
}
offsets = append(offsets, int32(offset))
}
d.offsets = offsets
}
func (d *indirectIndex) Contains(key string) bool {
return len(d.Entries(key)) > 0
}
func (d *indirectIndex) ContainsValue(key string, timestamp int64) bool {
return d.Entry(key, timestamp) != nil
}
func (d *indirectIndex) Type(key string) (byte, error) {
d.mu.RLock()
defer d.mu.RUnlock()
kb := []byte(key)
ofs := d.search(kb)
if ofs < len(d.b) {
n, _, err := readKey(d.b[ofs:])
if err != nil {
panic(fmt.Sprintf("error reading key: %v", err))
}
ofs += n
return d.b[ofs], nil
}
return 0, fmt.Errorf("key does not exist: %v", key)
}
func (d *indirectIndex) KeyRange() (string, string) {
return d.minKey, d.maxKey
}
func (d *indirectIndex) TimeRange() (int64, int64) {
return d.minTime, d.maxTime
}
// MarshalBinary returns a byte slice encoded version of the index.
func (d *indirectIndex) MarshalBinary() ([]byte, error) {
d.mu.RLock()
defer d.mu.RUnlock()
return d.b, nil
}
// UnmarshalBinary populates an index from an encoded byte slice
// representation of an index.
func (d *indirectIndex) UnmarshalBinary(b []byte) error {
d.mu.Lock()
defer d.mu.Unlock()
// Keep a reference to the actual index bytes
d.b = b
//var minKey, maxKey []byte
var minTime, maxTime int64 = math.MaxInt64, 0
// To create our "indirect" index, we need to find the location of all the keys in
// the raw byte slice. The keys are listed once each (in sorted order). Following
// each key is a time ordered list of index entry blocks for that key. The loop below
// basically skips across the slice keeping track of the counter when we are at a key
// field.
var i int32
for i < int32(len(b)) {
d.offsets = append(d.offsets, i)
// Skip to the start of the values
// key length value (2) + type (1) + length of key
i += 3 + int32(binary.BigEndian.Uint16(b[i:i+2]))
// count of index entries
count := int32(binary.BigEndian.Uint16(b[i : i+indexCountSize]))
i += indexCountSize
// Find the min time for the block
minT := int64(binary.BigEndian.Uint64(b[i : i+8]))
if minT < minTime {
minTime = minT
}
i += (count - 1) * indexEntrySize
// Find the max time for the block
maxT := int64(binary.BigEndian.Uint64(b[i+8 : i+16]))
if maxT > maxTime {
maxTime = maxT
}
i += indexEntrySize
}
firstOfs := d.offsets[0]
_, key, err := readKey(b[firstOfs:])
if err != nil {
return err
}
d.minKey = string(key)
lastOfs := d.offsets[len(d.offsets)-1]
_, key, err = readKey(b[lastOfs:])
if err != nil {
return err
}
d.maxKey = string(key)
d.minTime = minTime
d.maxTime = maxTime
return nil
}
func (d *indirectIndex) Size() uint32 {
d.mu.RLock()
defer d.mu.RUnlock()
return uint32(len(d.b))
}
// fileAccessor is file IO based block accessor. It provides access to blocks
// using a file IO based approach (seek, read, etc.)
type fileAccessor struct {
mu sync.Mutex
r io.ReadSeeker
index TSMIndex
}
func (f *fileAccessor) init() (TSMIndex, error) {
f.mu.Lock()
defer f.mu.Unlock()
// Verify it's a TSM file of the right version
if err := verifyVersion(f.r); err != nil {
return nil, err
}
// Current the readers size
size, err := f.r.Seek(0, os.SEEK_END)
if err != nil {
return nil, fmt.Errorf("init: failed to seek: %v", err)
}
indexEnd := size - 8
// Seek to index location pointer
_, err = f.r.Seek(-8, os.SEEK_END)
if err != nil {
return nil, fmt.Errorf("init: failed to seek to index ptr: %v", err)
}
// Read the absolute position of the start of the index
b := make([]byte, 8)
_, err = f.r.Read(b)
if err != nil {
return nil, fmt.Errorf("init: failed to read index ptr: %v", err)
}
indexStart := int64(binary.BigEndian.Uint64(b))
_, err = f.r.Seek(indexStart, os.SEEK_SET)
if err != nil {
return nil, fmt.Errorf("init: failed to seek to index: %v", err)
}
b = make([]byte, indexEnd-indexStart)
f.index = &directIndex{
blocks: map[string]*indexEntries{},
}
_, err = f.r.Read(b)
if err != nil {
return nil, fmt.Errorf("init: read index: %v", err)
}
if err := f.index.UnmarshalBinary(b); err != nil {
return nil, fmt.Errorf("init: unmarshal error: %v", err)
}
return f.index, nil
}
func (f *fileAccessor) read(key string, timestamp int64) ([]Value, error) {
entry := f.index.Entry(key, timestamp)
if entry == nil {
return nil, nil
}
return f.readBlock(entry, nil)
}
func (f *fileAccessor) readBlock(entry *IndexEntry, values []Value) ([]Value, error) {
b, err := f.readBytes(entry, nil)
if err != nil {
return nil, err
}
//TODO: Validate checksum
values, err = DecodeBlock(b, values)
if err != nil {
return nil, err
}
return values, nil
}
func (f *fileAccessor) readFloatBlock(entry *IndexEntry, values []FloatValue) ([]FloatValue, error) {
b, err := f.readBytes(entry, nil)
if err != nil {
return nil, err
}
// TODO: Validate checksum
values, err = DecodeFloatBlock(b, values)
if err != nil {
return nil, err
}
return values, nil
}
func (f *fileAccessor) readIntegerBlock(entry *IndexEntry, values []IntegerValue) ([]IntegerValue, error) {
b, err := f.readBytes(entry, nil)
if err != nil {
return nil, err
}
// TODO: Validate checksum
values, err = DecodeIntegerBlock(b, values)
if err != nil {
return nil, err
}
return values, nil
}
func (f *fileAccessor) readStringBlock(entry *IndexEntry, values []StringValue) ([]StringValue, error) {
b, err := f.readBytes(entry, nil)
if err != nil {
return nil, err
}
// TODO: Validate checksum
values, err = DecodeStringBlock(b, values)
if err != nil {
return nil, err
}
return values, nil
}
func (f *fileAccessor) readBooleanBlock(entry *IndexEntry, values []BooleanValue) ([]BooleanValue, error) {
b, err := f.readBytes(entry, nil)
if err != nil {
return nil, err
}
// TODO: Validate checksum
values, err = DecodeBooleanBlock(b, values)
if err != nil {
return nil, err
}
return values, nil
}
func (f *fileAccessor) readBytes(entry *IndexEntry, b []byte) ([]byte, error) {
f.mu.Lock()
defer f.mu.Unlock()
// TODO: remove this allocation
if b == nil {
b = make([]byte, entry.Size)
}
_, err := f.r.Seek(entry.Offset, os.SEEK_SET)
if err != nil {
return nil, err
}
if int(entry.Size) > len(b) {
b = make([]byte, entry.Size)
}
n, err := f.r.Read(b[:entry.Size])
if err != nil {
return nil, err
}
return b[4:n], nil
}
// ReadAll returns all values for a key in all blocks.
func (f *fileAccessor) readAll(key string) ([]Value, error) {
var values []Value
blocks := f.index.Entries(key)
if len(blocks) == 0 {
return values, nil
}
var temp []Value
// TODO: we can determine the max block size when loading the file create/re-use
// a reader level buf then.
b := make([]byte, 16*1024)
for _, block := range blocks {
b, err := f.readBytes(block, b)
if err != nil {
return nil, err
}
//TODO: Validate checksum
temp = temp[:0]
temp, err = DecodeBlock(b, temp)
if err != nil {
return nil, err
}
values = append(values, temp...)
}
return values, nil
}
func (f *fileAccessor) path() string {
f.mu.Lock()
defer f.mu.Unlock()
if fd, ok := f.r.(*os.File); ok {
return fd.Name()
}
return ""
}
func (f *fileAccessor) close() error {
f.mu.Lock()
defer f.mu.Unlock()
if c, ok := f.r.(io.Closer); ok {
return c.Close()
}
return nil
}
// mmapAccess is mmap based block accessor. It access blocks through an
// MMAP file interface.
type mmapAccessor struct {
mu sync.RWMutex
f *os.File
b []byte
index TSMIndex
}
func (m *mmapAccessor) init() (TSMIndex, error) {
m.mu.Lock()
defer m.mu.Unlock()
if err := verifyVersion(m.f); err != nil {
return nil, err
}
var err error
if _, err := m.f.Seek(0, 0); err != nil {
return nil, err
}
stat, err := m.f.Stat()
if err != nil {
return nil, err
}
m.b, err = mmap(m.f, 0, int(stat.Size()))
if err != nil {
return nil, err
}
indexOfsPos := len(m.b) - 8
indexStart := binary.BigEndian.Uint64(m.b[indexOfsPos : indexOfsPos+8])
m.index = NewIndirectIndex()
if err := m.index.UnmarshalBinary(m.b[indexStart:indexOfsPos]); err != nil {
return nil, err
}
return m.index, nil
}
func (m *mmapAccessor) read(key string, timestamp int64) ([]Value, error) {
entry := m.index.Entry(key, timestamp)
if entry == nil {
return nil, nil
}
return m.readBlock(entry, nil)
}
func (m *mmapAccessor) readBlock(entry *IndexEntry, values []Value) ([]Value, error) {
m.mu.RLock()
defer m.mu.RUnlock()
if int64(len(m.b)) < entry.Offset+int64(entry.Size) {
return nil, ErrTSMClosed
}
//TODO: Validate checksum
var err error
values, err = DecodeBlock(m.b[entry.Offset+4:entry.Offset+int64(entry.Size)], values)
if err != nil {
return nil, err
}
return values, nil
}
func (m *mmapAccessor) readFloatBlock(entry *IndexEntry, values []FloatValue) ([]FloatValue, error) {
m.mu.RLock()
defer m.mu.RUnlock()
if int64(len(m.b)) < entry.Offset+int64(entry.Size) {
return nil, ErrTSMClosed
}
//TODO: Validate checksum
var err error
values, err = DecodeFloatBlock(m.b[entry.Offset+4:entry.Offset+int64(entry.Size)], values)
if err != nil {
return nil, err
}
return values, nil
}
func (m *mmapAccessor) readIntegerBlock(entry *IndexEntry, values []IntegerValue) ([]IntegerValue, error) {
m.mu.RLock()
defer m.mu.RUnlock()
if int64(len(m.b)) < entry.Offset+int64(entry.Size) {
return nil, ErrTSMClosed
}
//TODO: Validate checksum
var err error
values, err = DecodeIntegerBlock(m.b[entry.Offset+4:entry.Offset+int64(entry.Size)], values)
if err != nil {
return nil, err
}
return values, nil
}
func (m *mmapAccessor) readStringBlock(entry *IndexEntry, values []StringValue) ([]StringValue, error) {
m.mu.RLock()
defer m.mu.RUnlock()
if int64(len(m.b)) < entry.Offset+int64(entry.Size) {
return nil, ErrTSMClosed
}
//TODO: Validate checksum
var err error
values, err = DecodeStringBlock(m.b[entry.Offset+4:entry.Offset+int64(entry.Size)], values)
if err != nil {
return nil, err
}
return values, nil
}
func (m *mmapAccessor) readBooleanBlock(entry *IndexEntry, values []BooleanValue) ([]BooleanValue, error) {
m.mu.RLock()
defer m.mu.RUnlock()
if int64(len(m.b)) < entry.Offset+int64(entry.Size) {
return nil, ErrTSMClosed
}
//TODO: Validate checksum
var err error
values, err = DecodeBooleanBlock(m.b[entry.Offset+4:entry.Offset+int64(entry.Size)], values)
if err != nil {
return nil, err
}
return values, nil
}
func (m *mmapAccessor) readBytes(entry *IndexEntry, b []byte) ([]byte, error) {
m.mu.RLock()
defer m.mu.RUnlock()
if int64(len(m.b)) < entry.Offset+int64(entry.Size) {
return nil, ErrTSMClosed
}
// return the bytes after the 4 byte checksum
return m.b[entry.Offset+4 : entry.Offset+int64(entry.Size)], nil
}
// ReadAll returns all values for a key in all blocks.
func (m *mmapAccessor) readAll(key string) ([]Value, error) {
blocks := m.index.Entries(key)
if len(blocks) == 0 {
return nil, nil
}
m.mu.RLock()
defer m.mu.RUnlock()
var temp []Value
var err error
var values []Value
for _, block := range blocks {
//TODO: Validate checksum
temp = temp[:0]
// The +4 is the 4 byte checksum length
temp, err = DecodeBlock(m.b[block.Offset+4:block.Offset+int64(block.Size)], temp)
if err != nil {
return nil, err
}
values = append(values, temp...)
}
return values, nil
}
func (m *mmapAccessor) path() string {
m.mu.RLock()
defer m.mu.RUnlock()
return m.f.Name()
}
func (m *mmapAccessor) close() error {
m.mu.Lock()
defer m.mu.Unlock()
if m.b == nil {
return nil
}
err := munmap(m.b)
if err != nil {
return err
}
m.b = nil
return m.f.Close()
}
type indexEntries struct {
Type byte
entries []*IndexEntry
}
func (a *indexEntries) Len() int { return len(a.entries) }
func (a *indexEntries) Swap(i, j int) { a.entries[i], a.entries[j] = a.entries[j], a.entries[i] }
func (a *indexEntries) Less(i, j int) bool {
return a.entries[i].MinTime < a.entries[j].MinTime
}
func (a *indexEntries) Append(entry ...*IndexEntry) {
a.entries = append(a.entries, entry...)
}
func (a *indexEntries) MarshalBinary() ([]byte, error) {
buf := make([]byte, len(a.entries)*indexEntrySize)
for i, entry := range a.entries {
entry.AppendTo(buf[indexEntrySize*i:])
}
return buf, nil
}
func (a *indexEntries) WriteTo(w io.Writer) (total int64, err error) {
var buf [indexEntrySize]byte
var n int
for _, entry := range a.entries {
entry.AppendTo(buf[:])
n, err = w.Write(buf[:])
total += int64(n)
if err != nil {
return total, err
}
}
return total, nil
}
func readKey(b []byte) (n int, key []byte, err error) {
// 2 byte size of key
n, size := 2, int(binary.BigEndian.Uint16(b[:2]))
// N byte key
key = b[n : n+size]
n += len(key)
return
}
func readEntries(b []byte) (n int, entries *indexEntries, err error) {
// 1 byte block type
blockType := b[n]
entries = &indexEntries{
Type: blockType,
entries: []*IndexEntry{},
}
n++
// 2 byte count of index entries
count := int(binary.BigEndian.Uint16(b[n : n+indexCountSize]))
n += indexCountSize
for i := 0; i < count; i++ {
ie := &IndexEntry{}
if err := ie.UnmarshalBinary(b[i*indexEntrySize+indexCountSize+indexTypeSize : i*indexEntrySize+indexCountSize+indexEntrySize+indexTypeSize]); err != nil {
return 0, nil, fmt.Errorf("readEntries: unmarshal error: %v", err)
}
entries.Append(ie)
n += indexEntrySize
}
return
}