Documentation
¶
Overview ¶
Package blockmanager
(C) Copyright Alex Gaetano Padula
Licensed under the Mozilla Public License, v. 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
https://www.mozilla.org/en-US/MPL/2.0/
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
Index ¶
Constants ¶
const Allotment = uint64(16) // How many blocks we can allot at once to the file. We allocate this many blocks once allocationTable is empty
const BlockSize = uint32(512) // Smaller the better, faster in our tests
const EndOfChain = uint64(0xFFFFFFFFFFFFFFFF) // Marker for end of blockchain (overflowed block)
const MagicNumber = uint32(0x57494C44) // "WILD"
const Version = uint32(1) // Version of the file format
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type BlockHeader ¶
type BlockHeader struct {
CRC uint32 // CRC32 checksum of the block header
BlockID uint64 // Unique ID of the block
DataSize uint64 // Size of the data in the block
NextBlock uint64 // ID of the next block in the chain (or EndOfChain if this is the last block)
}
BlockHeader represents the header of a block in the file
type BlockManager ¶
type BlockManager struct {
// contains filtered or unexported fields
}
BlockManager manages the allocation and deallocation of blocks in a file
func Open ¶
func Open(filename string, flag int, perm os.FileMode, syncOpt SyncOption, duration ...time.Duration) (*BlockManager, error)
Open opens a file and initializes the BlockManager.
func (*BlockManager) Append ¶
func (bm *BlockManager) Append(data []byte) (int64, error)
Append writes data to the file by allocating one or more blocks and returns the ID of the first block containing the data.
func (*BlockManager) Close ¶
func (bm *BlockManager) Close() error
Close closes the file and releases any resources held by the BlockManager.
func (*BlockManager) File ¶
func (bm *BlockManager) File() *os.File
File returns the associated file handle for the BlockManager
func (*BlockManager) Iterator ¶
func (bm *BlockManager) Iterator() *Iterator
Iterator returns an iterator for traversing the blocks in the file
func (*BlockManager) Read ¶
func (bm *BlockManager) Read(blockID int64) ([]byte, int64, error)
Read reads data from the file starting at the specified block ID. It follows the chain of blocks if the data spans multiple blocks. Returns the data, the final block ID (if chained) or the first block ID (if not chained), and any error.
type Header ¶
type Header struct {
CRC uint32 // CRC32 checksum of the header
MagicNumber uint32 // Magic number to identify the file format
Version uint32 // Version of the file format
BlockSize uint32 // Size of each block in bytes
Allotment uint64 // Number of blocks to allot at once
}
Header represents the header of the file
type Iterator ¶
type Iterator struct {
// contains filtered or unexported fields
}
Iterator is used to traverse the blocks in the file
func (*Iterator) BlockManager ¶
func (it *Iterator) BlockManager() *BlockManager
BlockManager returns the block manager pointer from iterator
type SyncOption ¶
type SyncOption int
SyncOption defines the synchronization options for the file
const ( SyncNone SyncOption = iota // Don't sync at all SyncFull // Do a sync after every write SyncPartial // Do a sync in the background at intervals )
Source Files