func TestRecordAllocator_Update(t *testing.T) {
fakeDataFile := utils.NewFakeDataFile(6)
if err := core.FormatDataFileIfNeeded(fakeDataFile); err != nil {
t.Fatal(err)
}
dataBuffer := dbio.NewDataBuffer(fakeDataFile, 4)
allocator := core.NewRecordAllocator(dataBuffer)
// Fill up a datablock up to its limit
maxData := dbio.DATABLOCK_SIZE - core.MIN_UTILIZATION - core.RECORD_HEADER_SIZE
contents := ""
for i := uint16(0); i < maxData; i++ {
contents += fmt.Sprintf("%d", i%10)
}
allocator.Add(&core.Record{ID: 1, Data: []byte(contents)})
// Add a new record that will go into the next datablock on the list
allocator.Add(&core.Record{ID: 2, Data: []byte("Some data")})
// Update records
rowID := core.RowID{DataBlockID: 3, LocalID: 0}
if err := allocator.Update(rowID, &core.Record{ID: 1, Data: []byte("NEW CONTENTS")}); err != nil {
t.Fatal(err)
}
rowID = core.RowID{DataBlockID: 4, LocalID: 0}
if err := allocator.Update(rowID, &core.Record{ID: 2, Data: []byte("EVEN MORE!")}); err != nil {
t.Fatal(err)
}
// Flush data to data blocks and ensure that things work after a reload
dataBuffer.Sync()
dataBuffer = dbio.NewDataBuffer(fakeDataFile, 4)
repo := core.NewDataBlockRepository(dataBuffer)
// Ensure blocks have been updated
recordBlock := repo.RecordBlock(3)
data, err := recordBlock.ReadRecordData(0)
if err != nil {
t.Fatal(err)
}
if string(data) != "NEW CONTENTS" {
t.Errorf("First record did not get updated, read `%s`", data)
}
recordBlock = repo.RecordBlock(4)
data, err = recordBlock.ReadRecordData(0)
if err != nil {
t.Fatal(err)
}
if string(data) != "EVEN MORE!" {
t.Errorf("Second record did not get updated, read `%s`", data)
}
}
func TestEvictsBlocksAfterFillingInAllFrames(t *testing.T) {
fakeDataFile := utils.NewFakeDataFileWithBlocks([][]byte{
[]byte{}, []byte{}, []byte{},
})
readCount := 0
original := fakeDataFile.ReadBlockFunc
fakeDataFile.ReadBlockFunc = func(id uint16, data []byte) error {
readCount += 1
return original(id, data)
}
buffer := dbio.NewDataBuffer(fakeDataFile, 2)
// From this point on, we fetch blocks in a way to ensure that we have multiple
// hits on different blocks and also force a couple cache misses
for blockId := 0; blockId < 3; blockId++ {
for i := 0; i < 10; i++ {
buffer.FetchBlock(uint16(blockId))
}
}
// Fetch block 1 again to ensure it is still in memory
buffer.FetchBlock(uint16(1))
if readCount != 3 {
t.Errorf("Read from datafile more than three times (total: %d times)", readCount)
}
// Force 2 cache misses
buffer.FetchBlock(0)
buffer.FetchBlock(1)
if readCount != 5 {
t.Error("Read from cache but should not do that")
}
}
func TestReturnsErrorsWhenSyncing(t *testing.T) {
fakeDataFile := utils.NewFakeDataFileWithBlocks([][]byte{
[]byte{}, []byte{},
})
expectedError := errors.New("BOOM")
fakeDataFile.WriteBlockFunc = func(id uint16, data []byte) error {
return expectedError
}
buffer := dbio.NewDataBuffer(fakeDataFile, 2)
buffer.FetchBlock(0)
buffer.FetchBlock(1)
if err := buffer.Sync(); err != nil {
t.Fatal("Unexpected error", err)
}
buffer.MarkAsDirty(1)
err := buffer.Sync()
if err == nil {
t.Fatal("Error not raised")
} else if err != expectedError {
t.Fatal("Unknown error raised")
}
}
func TestRecordAllocator_Add(t *testing.T) {
fakeDataFile := utils.NewFakeDataFile(7)
if err := core.FormatDataFileIfNeeded(fakeDataFile); err != nil {
t.Fatal(err)
}
dataBuffer := dbio.NewDataBuffer(fakeDataFile, 4)
allocator := core.NewRecordAllocator(dataBuffer)
// Fill up a datablock up to its limit
maxData := dbio.DATABLOCK_SIZE - core.MIN_UTILIZATION - core.RECORD_HEADER_SIZE
contents := ""
for i := uint16(0); i < maxData; i++ {
contents += fmt.Sprintf("%d", i%10)
}
allocator.Add(&core.Record{ID: uint32(1), Data: []byte(contents)})
// Add a new record that will go into the next datablock on the list
allocator.Add(&core.Record{ID: uint32(2), Data: []byte("Some data")})
// Flush data to data blocks and ensure that things work after a reload
dataBuffer.Sync()
dataBuffer = dbio.NewDataBuffer(fakeDataFile, 4)
repo := core.NewDataBlockRepository(dataBuffer)
blockMap := repo.DataBlocksMap()
// Ensure new blocks has been marked as used
if !blockMap.IsInUse(3) || !blockMap.IsInUse(4) {
t.Errorf("Blocks 3 and 4 should have been marked as in use")
}
// Ensure the blocks point to each other
firstRecordBlock := repo.RecordBlock(3)
if firstRecordBlock.NextBlockID() != 4 {
t.Errorf("First allocated block does not point to the next one")
}
secondRecordBlock := repo.RecordBlock(4)
if secondRecordBlock.PrevBlockID() != 3 {
t.Errorf("Second allocated block does not point to the previous one")
}
// Ensure the pointer for the next datablock that has free space has been updated
controlBlock := repo.ControlBlock()
if controlBlock.NextAvailableRecordsDataBlockID() != 4 {
t.Errorf("Did not update the pointer to the next datablock that allows insertion, got %d", controlBlock.NextAvailableRecordsDataBlockID())
}
}
func NewWithDataFile(dataFile dbio.DataFile) (SimpleJSONDB, error) {
if err := core.FormatDataFileIfNeeded(dataFile); err != nil {
return nil, err
}
dataBuffer := dbio.NewDataBuffer(dataFile, BUFFER_SIZE)
repo := core.NewDataBlockRepository(dataBuffer)
index := core.NewUint32Index(dataBuffer, BTREE_IDX_BRANCH_MAX_ENTRIES, BTREE_IDX_LEAF_MAX_ENTRIES)
return &simpleJSONDB{dataFile, dataBuffer, repo, index}, nil
}
func createIndex(t *testing.T, totalUsableBlocks, bufferFrames, branchCapacity int, leafCapacity int) core.Uint32Index {
fakeDataFile := utils.NewFakeDataFile(totalUsableBlocks + 4)
if err := core.FormatDataFileIfNeeded(fakeDataFile); err != nil {
t.Fatal(err)
}
dataBuffer := dbio.NewDataBuffer(fakeDataFile, bufferFrames)
index := core.NewUint32Index(dataBuffer, branchCapacity, leafCapacity)
index.Init()
return index
}
func TestFetchesBlockFromDataFile(t *testing.T) {
fakeDataBlock := []byte{0x10, 0xF0}
fakeDataFile := utils.NewFakeDataFileWithBlocks([][]byte{nil, fakeDataBlock})
dataBlock, err := dbio.NewDataBuffer(fakeDataFile, 1).FetchBlock(1)
if err != nil {
t.Fatal("Unexpected error", err)
}
if dataBlock.ID != 1 {
t.Errorf("ID doesn't match (expected %d got %d)", 1, dataBlock.ID)
}
if !utils.SlicesEqual(dataBlock.Data[0:2], fakeDataBlock) {
t.Errorf("Data blocks do not match (expected %x got %x)", fakeDataBlock, dataBlock.Data[0:2])
}
}
func TestSavesDirtyFramesOnSync(t *testing.T) {
fakeDataFile := utils.NewFakeDataFileWithBlocks([][]byte{
[]byte{}, []byte{}, []byte{},
})
blocksThatWereWritten := []uint16{}
fakeDataFile.WriteBlockFunc = func(id uint16, data []byte) error {
blocksThatWereWritten = append(blocksThatWereWritten, id)
return nil
}
buffer := dbio.NewDataBuffer(fakeDataFile, 3)
// Read the 3 blocks and flag two as dirty
buffer.FetchBlock(0)
buffer.MarkAsDirty(0)
buffer.FetchBlock(1)
// Not dirty
buffer.FetchBlock(2)
buffer.MarkAsDirty(2)
if err := buffer.Sync(); err != nil {
t.Fatal(err)
}
if len(blocksThatWereWritten) != 2 {
t.Fatalf("Should have written 2 blocks, wrote %v", blocksThatWereWritten)
}
if blocksThatWereWritten[0] != 0 && blocksThatWereWritten[1] != 0 {
t.Errorf("Should have written the block 0, wrote %v", blocksThatWereWritten)
}
if blocksThatWereWritten[0] != 2 && blocksThatWereWritten[1] != 2 {
t.Errorf("Should have written the block 2, wrote %v", blocksThatWereWritten)
}
blocksThatWereWritten = []uint16{}
if err := buffer.Sync(); err != nil {
t.Fatal(err)
}
if len(blocksThatWereWritten) != 0 {
t.Fatalf("Blocks have already been writen, wrote %v again", blocksThatWereWritten)
}
}
func TestFetchBlockCachesData(t *testing.T) {
fakeDataFile := utils.NewFakeDataFileWithBlocks([][]byte{nil, []byte{}})
readCount := 0
original := fakeDataFile.ReadBlockFunc
fakeDataFile.ReadBlockFunc = func(id uint16, data []byte) error {
readCount += 1
return original(id, data)
}
buffer := dbio.NewDataBuffer(fakeDataFile, 1)
for i := 0; i < 10; i++ {
buffer.FetchBlock(1)
}
if readCount > 1 {
t.Errorf("Read from datafile more than once (total: %d times)", readCount)
}
}
func TestSavesDirtyFramesWhenEvicting(t *testing.T) {
fakeDataBlock := []byte{0x00, 0x01, 0x02}
fakeDataFile := utils.NewFakeDataFileWithBlocks([][]byte{
fakeDataBlock, []byte{}, []byte{}, []byte{},
})
blockThatWasWritten := uint16(999)
bytesWritten := []byte{}
fakeDataFile.WriteBlockFunc = func(id uint16, data []byte) error {
blockThatWasWritten = id
bytesWritten = data
return nil
}
buffer := dbio.NewDataBuffer(fakeDataFile, 2)
// Read the first 2 blocks and flag the first one as dirty
buffer.FetchBlock(0)
buffer.FetchBlock(1)
buffer.MarkAsDirty(0)
// Evict the frame 1 by loading a third frame
buffer.FetchBlock(2)
// Evict the frame 0 by loading a fourth frame
buffer.FetchBlock(3)
if blockThatWasWritten == 999 {
t.Fatalf("Block was not saved to disk (%d)", blockThatWasWritten)
}
if blockThatWasWritten != 0 {
t.Errorf("Unknown block saved to disk (%d)", blockThatWasWritten)
}
if !utils.SlicesEqual(bytesWritten[0:3], fakeDataBlock) {
t.Errorf("Invalid data saved to disk %x", bytesWritten[0:3])
}
}
func TestDiscardsUnmodifiedFrames(t *testing.T) {
fakeDataFile := utils.NewFakeDataFileWithBlocks([][]byte{
[]byte{}, []byte{}, []byte{},
})
wroteToDisk := false
fakeDataFile.WriteBlockFunc = func(id uint16, data []byte) error {
wroteToDisk = true
return nil
}
buffer := dbio.NewDataBuffer(fakeDataFile, 2)
// Read the first 2 blocks
buffer.FetchBlock(0)
buffer.FetchBlock(1)
// Evict the first frame (by loading a third frame)
buffer.FetchBlock(2)
if wroteToDisk {
t.Fatal("No blocks should have been saved to disk")
}
}
func FormatDataFileIfNeeded(dataFile dbio.DataFile) error {
dataBuffer := dbio.NewDataBuffer(dataFile, 5)
repo := NewDataBlockRepository(dataBuffer)
controlBlock := repo.ControlBlock()
if controlBlock.NextAvailableRecordsDataBlockID() != 0 {
log.Println("DB_FORMAT_SKIPPED")
return nil
}
log.Println("DB_FORMAT_DATA_FILE")
controlBlock.Format()
dataBuffer.MarkAsDirty(controlBlock.DataBlockID())
blockMap := repo.DataBlocksMap()
// 3 -> 1 for the control block
// + 2 for the datablocks bitmap
// + 1 for the first block used by records
for i := uint16(0); i < 4; i++ {
blockMap.MarkAsUsed(i)
}
return dataBuffer.Sync()
}
func TestDataBlocksMap(t *testing.T) {
fakeDataFile := utils.NewFakeDataFile(3)
dataBuffer := dbio.NewDataBuffer(fakeDataFile, 2)
dbm := &dataBlocksMap{dataBuffer}
// First position is free by default
if free := dbm.FirstFree(); free != 0 {
t.Errorf("Unexpected result for fetching the first free block")
}
// Mark some blocks as being in use
dbm.MarkAsUsed(0)
dbm.MarkAsUsed(1)
dbm.MarkAsUsed(2)
dbm.MarkAsUsed(5)
dbm.MarkAsUsed(dbio.DATABLOCK_SIZE + 100)
// Ensure it spots the gap
if free := dbm.FirstFree(); free != 3 {
t.Errorf("Unexpected result for fetching the first free block after some interaction with the map")
}
// Ensure it reclaims the free block
dbm.MarkAsFree(2)
if free := dbm.FirstFree(); free != 2 {
t.Errorf("Did not reclaim the new free block")
}
// Ensure it works across data blocks
if !dbm.IsInUse(1) {
t.Errorf("Expected datablock 1 to be in use")
}
if !dbm.IsInUse(dbio.DATABLOCK_SIZE + 100) {
t.Errorf("Expected datablock %d to be in use", dbio.DATABLOCK_SIZE+100)
}
// // Clear all positions first
max := dbio.DATABLOCK_SIZE * 2
for i := 0; i < max; i++ {
dbm.MarkAsFree(uint16(i))
}
// Fill in the whole map
for i := 0; i < max; i++ {
dbm.MarkAsUsed(uint16(i))
if free := dbm.FirstFree(); free != uint16(i+1) {
t.Fatalf("Something is wrong with detecting the first free block after %d was marked as being in use, got %d", i, free)
}
}
// Ensure it detects that there are no more available blocks
if !dbm.AllInUse() {
t.Error("Expected all positions to be in use")
}
dbm.MarkAsFree(2)
if dbm.AllInUse() {
t.Error("Expected all positions to not be in use")
}
// Ensure that the blocks / frames were flagged as dirty
blocksThatWereWritten := []uint16{}
fakeDataFile.WriteBlockFunc = func(id uint16, data []byte) error {
blocksThatWereWritten = append(blocksThatWereWritten, id)
return nil
}
dataBuffer.Sync()
if len(blocksThatWereWritten) != 2 {
t.Fatalf("Should have written 2 blocks, wrote %v", blocksThatWereWritten)
}
}
func TestRecordAllocator_Remove(t *testing.T) {
fakeDataFile := utils.NewFakeDataFile(8)
dataBuffer := dbio.NewDataBuffer(fakeDataFile, 5)
if err := core.FormatDataFileIfNeeded(fakeDataFile); err != nil {
t.Fatal(err)
}
allocator := core.NewRecordAllocator(dataBuffer)
// Prepare data to fill up a datablock up to its limit
maxData := dbio.DATABLOCK_SIZE - core.MIN_UTILIZATION - core.RECORD_HEADER_SIZE
contents := ""
for i := uint16(0); i < maxData; i++ {
contents += fmt.Sprintf("%d", i%10)
}
// Insert data into 3 different blocks
allocator.Add(&core.Record{ID: uint32(3), Data: []byte(contents)})
allocator.Add(&core.Record{ID: uint32(4), Data: []byte(contents)})
allocator.Add(&core.Record{ID: uint32(5), Data: []byte(contents)})
allocator.Add(&core.Record{ID: uint32(6), Data: []byte("Some data")})
allocator.Add(&core.Record{ID: uint32(7), Data: []byte("More data")})
// Free up some datablocks
allocator.Remove(core.RowID{DataBlockID: 3, LocalID: 0})
allocator.Remove(core.RowID{DataBlockID: 5, LocalID: 0})
// Free part of another datablock
allocator.Remove(core.RowID{DataBlockID: 6, LocalID: 0})
// Flush data to data blocks and ensure that things work after a reload
dataBuffer.Sync()
dataBuffer = dbio.NewDataBuffer(fakeDataFile, 4)
repo := core.NewDataBlockRepository(dataBuffer)
blockMap := repo.DataBlocksMap()
// Ensure blocks have been marked as free again
if blockMap.IsInUse(3) {
t.Errorf("Block 3 should have been marked as free")
}
if blockMap.IsInUse(5) {
t.Errorf("Block 5 should have been marked as free")
}
// Ensure the linked list is set up properly
// First records datablock is now at block 4
controlBlock := repo.ControlBlock()
if controlBlock.FirstRecordDataBlock() != 4 {
t.Fatalf("First record datablock is set to the wrong block, found %d", controlBlock.FirstRecordDataBlock())
}
// Then the next block on the chain is at block 6
recordBlock := repo.RecordBlock(4)
if recordBlock.NextBlockID() != 6 {
t.Fatalf("First record datablock next block pointer is set to the wrong block (%d)", recordBlock.NextBlockID())
}
// And the block 6 points back to the block 4
recordBlock = repo.RecordBlock(6)
if recordBlock.PrevBlockID() != 4 {
t.Fatalf("Second record datablock previous block pointer is incorrect (%d)", recordBlock.PrevBlockID())
}
}
func TestRecordAllocator_ChainedRows(t *testing.T) {
fakeDataFile := utils.NewFakeDataFile(11)
dataBuffer := dbio.NewDataBuffer(fakeDataFile, 5)
if err := core.FormatDataFileIfNeeded(fakeDataFile); err != nil {
t.Fatal(err)
}
allocator := core.NewRecordAllocator(dataBuffer)
// Prepare data to fill up a datablock close to its limit
maxData := dbio.DATABLOCK_SIZE - core.MIN_UTILIZATION - core.RECORD_HEADER_SIZE
contents := ""
for i := uint16(0); i < maxData; i++ {
contents += fmt.Sprintf("%d", i%10)
}
// Insert data into 3 different blocks
dummy, _ := allocator.Add(&core.Record{ID: uint32(3), Data: []byte(contents[0 : maxData-100])})
chainedRowRowID, _ := allocator.Add(&core.Record{ID: uint32(4), Data: []byte(contents)})
removedChainedRowID, _ := allocator.Add(&core.Record{ID: uint32(5), Data: []byte(contents)})
allocator.Add(&core.Record{ID: uint32(6), Data: []byte("Some data")})
allocator.Add(&core.Record{ID: uint32(7), Data: []byte("More data")})
// Ensure that the blocks are chained
if dummy.DataBlockID != chainedRowRowID.DataBlockID {
t.Fatalf("Did not create a chained row, expected record to be written on block %d but was written on block %d", dummy.DataBlockID, chainedRowRowID.DataBlockID)
}
// Ensure we exercise the code path that deletes chained rows
allocator.Remove(dummy)
allocator.Remove(removedChainedRowID)
// Flush data to data blocks and ensure that things work after a reload
dataBuffer.Sync()
dataBuffer = dbio.NewDataBuffer(fakeDataFile, 10)
repo := core.NewDataBlockRepository(dataBuffer)
allocator = core.NewRecordAllocator(dataBuffer)
// Ensure the records can be read after a reload
recordBlock := repo.RecordBlock(chainedRowRowID.DataBlockID)
first, err := recordBlock.ReadRecordData(chainedRowRowID.LocalID)
if err != nil {
t.Fatal(err)
}
chainedRowID, err := recordBlock.ChainedRowID(chainedRowRowID.LocalID)
if err != nil {
t.Fatal(err)
}
recordBlock = repo.RecordBlock(chainedRowID.DataBlockID)
second, err := recordBlock.ReadRecordData(chainedRowID.LocalID)
if string(first)+string(second) != contents {
t.Errorf("Invalid contents found for record, found `%s` and `%s`, expected `%s`", first, second, contents)
}
// Ensure deletes clear out headers properly
recordBlock = repo.RecordBlock(removedChainedRowID.DataBlockID)
if _, err = recordBlock.ReadRecordData(removedChainedRowID.LocalID); err == nil {
t.Fatal("Did not clear out the record header of one of the a chained rows deleted")
}
recordBlock = repo.RecordBlock(removedChainedRowID.DataBlockID + 1)
if _, err = recordBlock.ReadRecordData(0); err == nil {
t.Fatal("Did not clear out the record header of the next block of the chained row")
}
dataBuffer.Sync()
dataBuffer = dbio.NewDataBuffer(fakeDataFile, 10)
repo = core.NewDataBlockRepository(dataBuffer)
allocator = core.NewRecordAllocator(dataBuffer)
// Add and update a chained row that spans 3 blocks
bigContents := contents + contents + contents
chainedUpdateRowID, _ := allocator.Add(&core.Record{ID: uint32(9), Data: []byte(bigContents)})
// Keep track of the list of the following row ids of the chained row
rowIDs := []core.RowID{}
recordBlock = repo.RecordBlock(chainedUpdateRowID.DataBlockID)
nextRowID, err := recordBlock.ChainedRowID(chainedUpdateRowID.LocalID)
if err != nil {
t.Fatal(err)
}
rowIDs = append(rowIDs, nextRowID)
recordBlock = repo.RecordBlock(nextRowID.DataBlockID)
nextRowID, err = recordBlock.ChainedRowID(nextRowID.LocalID)
if err != nil {
t.Fatal(err)
}
rowIDs = append(rowIDs, nextRowID)
if len(rowIDs) != 2 {
t.Errorf("Spread record on more blocks than expected %+v", rowIDs)
}
// Change record to be really small
allocator.Update(chainedUpdateRowID, &core.Record{ID: uint32(9), Data: []byte("a string")})
// Ensure the next element on the chained row list got cleared
for _, rowID := range rowIDs {
_, err := repo.RecordBlock(rowID.DataBlockID).ReadRecordData(rowID.LocalID)
if err == nil {
t.Errorf("Did not clear chained row %+v", rowID)
}
}
// Ensure we can read it
recordBlock = repo.RecordBlock(chainedUpdateRowID.DataBlockID)
data, _ := recordBlock.ReadRecordData(chainedRowID.LocalID)
if string(data) != "a string" {
t.Error("Invalid contents found for record")
}
}