leveldb.writebatch source code

1 /**
2  * D-LevelDB Write Batch
3  *
4  * WriteBatch holds multiple writes that can be applied to an open DB in a sinlge
5  * atomic update.
6  *
7  * Copyright: Copyright © 2013 Byron Heads
8  * License: <a href="http://www.boost.org/LICENSE_1_0.txt">Boost License 1.0</a>.
9  * Authors: Byron Heads
10 */
11 /*          Copyright  © 2013 Byron Heads
12  * Distributed under the Boost Software License, Version 1.0.
13  *    (See accompanying file LICENSE_1_0.txt or copy at
14  *          http://www.boost.org/LICENSE_1_0.txt)
15  */
16 module leveldb.writebatch;
17 /+
18 
19 private import  leveldb.exceptions,
20                 leveldb.slice;
21 private import deimos.leveldb.leveldb;
22 
23 class WriteBatch
24 {
25 private:
26     leveldb_writebatch_t _ptr;
27 
28 package:
29     @property
30     inout(leveldb_writebatch_t) ptr() inout
31     {
32         return _ptr;
33     }
34 
35 public:
36     this()
37     {
38         if((_ptr = leveldb_writebatch_create()) is null)
39             throw new LeveldbException("Failed to create batch writer");
40     }
41 
42     ~this()
43     {
44         if(valid)
45         {
46             leveldb_writebatch_destroy(_ptr);
47             _ptr = null;
48         }
49     }
50 
51     @property
52     void clear()
53     {
54         leveldb_writebatch_clear(_ptr);
55     }
56 
57     void put(K, V)(K key, V val)
58     {
59         put_raw(key._lib_obj_ptr__, key._lib_obj_size__, val._lib_obj_ptr__, val._lib_obj_size__);
60     }
61 
62     private
63     void put_raw(const(char*) key, size_t keylen, const(char*)val, size_t vallen)
64     {
65         leveldb_writebatch_put(_ptr, key, keylen, val, vallen);
66     }
67 
68     void del(T)(T key)
69     {
70         leveldb_writebatch_delete(_ptr, key._lib_obj_ptr__, key._lib_obj_size__);
71     }
72 
73     void iterate(Visitor visitor)
74     {
75         leveldb_writebatch_iterate(_ptr, cast(void*)&visitor,
76             &batchPut, &batchDel);
77     }
78 
79     void iterate(void delegate(Slice key, Slice value) puts,
80         void delegate(Slice key) dels)
81     {
82         iterate(Visitor(puts, dels));
83     }
84 
85     @property
86     bool valid() inout
87     {
88         return _ptr !is null;
89     }
90 
91     static struct Visitor
92     {
93         void delegate(Slice key, Slice value) puts;
94         void delegate(Slice key) dels;
95     }
96 } // WriteBatch
97 
98 
99 private:
100 extern(C):
101 
102 void batchPut(void* state, const char* k, size_t klen, const char* v, size_t vlen)
103 {
104     auto visitor = cast(WriteBatch.Visitor*)state;
105     visitor.puts(Slice(cast(void*)k, klen, true), Slice(cast(void*)v, vlen, true));
106 }
107 
108 void batchDel(void* state, const char* k, size_t klen)
109 {
110     auto visitor = cast(WriteBatch.Visitor*)state;
111     visitor.dels(Slice(cast(void*)k, klen, true));
112 }
113 +/