93 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			93 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| // Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
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| // All rights reserved.
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| //
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| // Use of this source code is governed by a BSD-style license that can be
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| // found in the LICENSE file.
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| 
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| // Package leveldb provides implementation of LevelDB key/value database.
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| //
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| // Create or open a database:
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| //
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| //	// The returned DB instance is safe for concurrent use. Which mean that all
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| //	// DB's methods may be called concurrently from multiple goroutine.
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| //	db, err := leveldb.OpenFile("path/to/db", nil)
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| //	...
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| //	defer db.Close()
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| //	...
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| //
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| // Read or modify the database content:
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| //
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| //	// Remember that the contents of the returned slice should not be modified.
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| //	data, err := db.Get([]byte("key"), nil)
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| //	...
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| //	err = db.Put([]byte("key"), []byte("value"), nil)
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| //	...
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| //	err = db.Delete([]byte("key"), nil)
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| //	...
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| //
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| // Iterate over database content:
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| //
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| //	iter := db.NewIterator(nil, nil)
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| //	for iter.Next() {
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| //		// Remember that the contents of the returned slice should not be modified, and
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| //		// only valid until the next call to Next.
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| //		key := iter.Key()
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| //		value := iter.Value()
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| //		...
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| //	}
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| //	iter.Release()
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| //	err = iter.Error()
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| //	...
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| //
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| // Iterate over subset of database content with a particular prefix:
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| //	iter := db.NewIterator(util.BytesPrefix([]byte("foo-")), nil)
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| //	for iter.Next() {
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| //		// Use key/value.
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| //		...
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| //	}
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| //	iter.Release()
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| //	err = iter.Error()
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| //	...
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| //
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| // Seek-then-Iterate:
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| //
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| // 	iter := db.NewIterator(nil, nil)
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| // 	for ok := iter.Seek(key); ok; ok = iter.Next() {
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| // 		// Use key/value.
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| // 		...
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| // 	}
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| // 	iter.Release()
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| // 	err = iter.Error()
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| // 	...
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| //
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| // Iterate over subset of database content:
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| //
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| // 	iter := db.NewIterator(&util.Range{Start: []byte("foo"), Limit: []byte("xoo")}, nil)
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| // 	for iter.Next() {
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| // 		// Use key/value.
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| // 		...
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| // 	}
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| // 	iter.Release()
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| // 	err = iter.Error()
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| // 	...
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| //
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| // Batch writes:
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| //
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| //	batch := new(leveldb.Batch)
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| //	batch.Put([]byte("foo"), []byte("value"))
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| //	batch.Put([]byte("bar"), []byte("another value"))
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| //	batch.Delete([]byte("baz"))
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| //	err = db.Write(batch, nil)
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| //	...
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| //
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| // Use bloom filter:
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| //
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| //	o := &opt.Options{
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| //		Filter: filter.NewBloomFilter(10),
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| //	}
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| //	db, err := leveldb.OpenFile("path/to/db", o)
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| //	...
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| //	defer db.Close()
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| //	...
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| package leveldb
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