1 /**
2  * Orthanc - A Lightweight, RESTful DICOM Store
3  *
4  * Copyright (C) 2012-2016 Sebastien Jodogne <s.jodogne@orthanc-labs.com>,
5  * Medical Physics Department, CHU of Liege, Belgium
6  *
7  * Copyright (c) 2012 The Chromium Authors. All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions are
11  * met:
12  *
13  *    * Redistributions of source code must retain the above copyright
14  * notice, this list of conditions and the following disclaimer.
15  *    * Redistributions in binary form must reproduce the above
16  * copyright notice, this list of conditions and the following disclaimer
17  * in the documentation and/or other materials provided with the
18  * distribution.
19  *    * Neither the name of Google Inc., the name of the CHU of Liege,
20  * nor the names of its contributors may be used to endorse or promote
21  * products derived from this software without specific prior written
22  * permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
30  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
34  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  **/
36 
37 
38 #pragma once
39 
40 #include "Statement.h"
41 #include "IScalarFunction.h"
42 #include "SQLiteTypes.h"
43 
44 #include <string>
45 #include <map>
46 
47 #define SQLITE_FROM_HERE ::Orthanc::SQLite::StatementId(__FILE__, __LINE__)
48 
49 namespace Orthanc
50 {
51   namespace SQLite
52   {
53     class ORTHANC_PUBLIC Connection : NonCopyable
54     {
55       friend class Statement;
56       friend class Transaction;
57 
58     private:
59       // All cached statements. Keeping a reference to these statements means that
60       // they'll remain active.
61       typedef std::map<StatementId, StatementReference*>  CachedStatements;
62       CachedStatements cachedStatements_;
63 
64       // The actual sqlite database. Will be NULL before Init has been called or if
65       // Init resulted in an error.
66       sqlite3* db_;
67 
68       // Number of currently-nested transactions.
69       int transactionNesting_;
70 
71       // True if any of the currently nested transactions have been rolled back.
72       // When we get to the outermost transaction, this will determine if we do
73       // a rollback instead of a commit.
74       bool needsRollback_;
75 
76       void ClearCache();
77 
78       void CheckIsOpen() const;
79 
GetWrappedObject()80       sqlite3* GetWrappedObject()
81       {
82         return db_;
83       }
84 
85       StatementReference& GetCachedStatement(const StatementId& id,
86                                              const char* sql);
87 
88       bool DoesTableOrIndexExist(const char* name,
89                                  const char* type) const;
90 
91       void DoRollback();
92 
93     public:
94       // The database is opened by calling Open[InMemory](). Any uncommitted
95       // transactions will be rolled back when this object is deleted.
96       Connection();
97       ~Connection();
98 
99       void Open(const std::string& path);
100 
101       void OpenInMemory();
102 
103       void Close();
104 
105       bool Execute(const char* sql);
106 
107       bool Execute(const std::string& sql);
108 
109       void FlushToDisk();
110 
111       IScalarFunction* Register(IScalarFunction* func);  // Takes the ownership of the function
112 
113       // Info querying -------------------------------------------------------------
114 
115       // Used to check a |sql| statement for syntactic validity. If the
116       // statement is valid SQL, returns true.
117       bool IsSQLValid(const char* sql);
118 
119       // Returns true if the given table exists.
120       bool DoesTableExist(const char* table_name) const;
121 
122       // Returns true if the given index exists.
123       bool DoesIndexExist(const char* index_name) const;
124 
125       // Returns true if a column with the given name exists in the given table.
126       bool DoesColumnExist(const char* table_name, const char* column_name) const;
127 
128       // Returns sqlite's internal ID for the last inserted row. Valid only
129       // immediately after an insert.
130       int64_t GetLastInsertRowId() const;
131 
132       // Returns sqlite's count of the number of rows modified by the last
133       // statement executed. Will be 0 if no statement has executed or the database
134       // is closed.
135       int GetLastChangeCount() const;
136 
137       // Errors --------------------------------------------------------------------
138 
139       // Returns the error code associated with the last sqlite operation.
140       int GetErrorCode() const;
141 
142       // Returns the errno associated with GetErrorCode().  See
143       // SQLITE_LAST_ERRNO in SQLite documentation.
144       int GetLastErrno() const;
145 
146       // Returns a pointer to a statically allocated string associated with the
147       // last sqlite operation.
148       const char* GetErrorMessage() const;
149 
150 
151       // Diagnostics (for unit tests) ----------------------------------------------
152 
153       int ExecuteAndReturnErrorCode(const char* sql);
154 
155       bool HasCachedStatement(const StatementId& id) const;
156 
157       int GetTransactionNesting() const;
158 
159       // Transactions --------------------------------------------------------------
160 
161       bool BeginTransaction();
162       void RollbackTransaction();
163       bool CommitTransaction();
164     };
165   }
166 }
167