aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/libraries/sqlite/win32/os.h
diff options
context:
space:
mode:
Diffstat (limited to 'libraries/sqlite/win32/os.h')
-rwxr-xr-xlibraries/sqlite/win32/os.h284
1 files changed, 284 insertions, 0 deletions
diff --git a/libraries/sqlite/win32/os.h b/libraries/sqlite/win32/os.h
new file mode 100755
index 0000000..554952d
--- /dev/null
+++ b/libraries/sqlite/win32/os.h
@@ -0,0 +1,284 @@
1/*
2** 2001 September 16
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11******************************************************************************
12**
13** This header file (together with is companion C source-code file
14** "os.c") attempt to abstract the underlying operating system so that
15** the SQLite library will work on both POSIX and windows systems.
16**
17** This header file is #include-ed by sqliteInt.h and thus ends up
18** being included by every source file.
19*/
20#ifndef _SQLITE_OS_H_
21#define _SQLITE_OS_H_
22
23/*
24** Figure out if we are dealing with Unix, Windows, or some other
25** operating system. After the following block of preprocess macros,
26** all of OS_UNIX, OS_WIN, OS_OS2, and OS_OTHER will defined to either
27** 1 or 0. One of the four will be 1. The other three will be 0.
28*/
29#if defined(OS_OTHER)
30# if OS_OTHER==1
31# undef OS_UNIX
32# define OS_UNIX 0
33# undef OS_WIN
34# define OS_WIN 0
35# undef OS_OS2
36# define OS_OS2 0
37# else
38# undef OS_OTHER
39# endif
40#endif
41#if !defined(OS_UNIX) && !defined(OS_OTHER)
42# define OS_OTHER 0
43# ifndef OS_WIN
44# if defined(_WIN32) || defined(WIN32) || defined(__CYGWIN__) || defined(__MINGW32__) || defined(__BORLANDC__)
45# define OS_WIN 1
46# define OS_UNIX 0
47# define OS_OS2 0
48# elif defined(__EMX__) || defined(_OS2) || defined(OS2) || defined(_OS2_) || defined(__OS2__)
49# define OS_WIN 0
50# define OS_UNIX 0
51# define OS_OS2 1
52# else
53# define OS_WIN 0
54# define OS_UNIX 1
55# define OS_OS2 0
56# endif
57# else
58# define OS_UNIX 0
59# define OS_OS2 0
60# endif
61#else
62# ifndef OS_WIN
63# define OS_WIN 0
64# endif
65#endif
66
67
68
69/*
70** Define the maximum size of a temporary filename
71*/
72#if OS_WIN
73# include <windows.h>
74# define SQLITE_TEMPNAME_SIZE (MAX_PATH+50)
75#elif OS_OS2
76# if (__GNUC__ > 3 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3) && defined(OS2_HIGH_MEMORY)
77# include <os2safe.h> /* has to be included before os2.h for linking to work */
78# endif
79# define INCL_DOSDATETIME
80# define INCL_DOSFILEMGR
81# define INCL_DOSERRORS
82# define INCL_DOSMISC
83# define INCL_DOSPROCESS
84# define INCL_DOSMODULEMGR
85# include <os2.h>
86# define SQLITE_TEMPNAME_SIZE (CCHMAXPATHCOMP)
87#else
88# define SQLITE_TEMPNAME_SIZE 200
89#endif
90
91/* If the SET_FULLSYNC macro is not defined above, then make it
92** a no-op
93*/
94#ifndef SET_FULLSYNC
95# define SET_FULLSYNC(x,y)
96#endif
97
98/*
99** The default size of a disk sector
100*/
101#ifndef SQLITE_DEFAULT_SECTOR_SIZE
102# define SQLITE_DEFAULT_SECTOR_SIZE 512
103#endif
104
105/*
106** Temporary files are named starting with this prefix followed by 16 random
107** alphanumeric characters, and no file extension. They are stored in the
108** OS's standard temporary file directory, and are deleted prior to exit.
109** If sqlite is being embedded in another program, you may wish to change the
110** prefix to reflect your program's name, so that if your program exits
111** prematurely, old temporary files can be easily identified. This can be done
112** using -DSQLITE_TEMP_FILE_PREFIX=myprefix_ on the compiler command line.
113**
114** 2006-10-31: The default prefix used to be "sqlite_". But then
115** Mcafee started using SQLite in their anti-virus product and it
116** started putting files with the "sqlite" name in the c:/temp folder.
117** This annoyed many windows users. Those users would then do a
118** Google search for "sqlite", find the telephone numbers of the
119** developers and call to wake them up at night and complain.
120** For this reason, the default name prefix is changed to be "sqlite"
121** spelled backwards. So the temp files are still identified, but
122** anybody smart enough to figure out the code is also likely smart
123** enough to know that calling the developer will not help get rid
124** of the file.
125*/
126#ifndef SQLITE_TEMP_FILE_PREFIX
127# define SQLITE_TEMP_FILE_PREFIX "etilqs_"
128#endif
129
130/*
131** If using an alternative OS interface, then we must have an "os_other.h"
132** header file available for that interface. Presumably the "os_other.h"
133** header file contains #defines similar to those above.
134*/
135#if OS_OTHER
136# include "os_other.h"
137#endif
138
139
140/*
141** The following values may be passed as the second argument to
142** sqlite3OsLock(). The various locks exhibit the following semantics:
143**
144** SHARED: Any number of processes may hold a SHARED lock simultaneously.
145** RESERVED: A single process may hold a RESERVED lock on a file at
146** any time. Other processes may hold and obtain new SHARED locks.
147** PENDING: A single process may hold a PENDING lock on a file at
148** any one time. Existing SHARED locks may persist, but no new
149** SHARED locks may be obtained by other processes.
150** EXCLUSIVE: An EXCLUSIVE lock precludes all other locks.
151**
152** PENDING_LOCK may not be passed directly to sqlite3OsLock(). Instead, a
153** process that requests an EXCLUSIVE lock may actually obtain a PENDING
154** lock. This can be upgraded to an EXCLUSIVE lock by a subsequent call to
155** sqlite3OsLock().
156*/
157#define NO_LOCK 0
158#define SHARED_LOCK 1
159#define RESERVED_LOCK 2
160#define PENDING_LOCK 3
161#define EXCLUSIVE_LOCK 4
162
163/*
164** File Locking Notes: (Mostly about windows but also some info for Unix)
165**
166** We cannot use LockFileEx() or UnlockFileEx() on Win95/98/ME because
167** those functions are not available. So we use only LockFile() and
168** UnlockFile().
169**
170** LockFile() prevents not just writing but also reading by other processes.
171** A SHARED_LOCK is obtained by locking a single randomly-chosen
172** byte out of a specific range of bytes. The lock byte is obtained at
173** random so two separate readers can probably access the file at the
174** same time, unless they are unlucky and choose the same lock byte.
175** An EXCLUSIVE_LOCK is obtained by locking all bytes in the range.
176** There can only be one writer. A RESERVED_LOCK is obtained by locking
177** a single byte of the file that is designated as the reserved lock byte.
178** A PENDING_LOCK is obtained by locking a designated byte different from
179** the RESERVED_LOCK byte.
180**
181** On WinNT/2K/XP systems, LockFileEx() and UnlockFileEx() are available,
182** which means we can use reader/writer locks. When reader/writer locks
183** are used, the lock is placed on the same range of bytes that is used
184** for probabilistic locking in Win95/98/ME. Hence, the locking scheme
185** will support two or more Win95 readers or two or more WinNT readers.
186** But a single Win95 reader will lock out all WinNT readers and a single
187** WinNT reader will lock out all other Win95 readers.
188**
189** The following #defines specify the range of bytes used for locking.
190** SHARED_SIZE is the number of bytes available in the pool from which
191** a random byte is selected for a shared lock. The pool of bytes for
192** shared locks begins at SHARED_FIRST.
193**
194** These #defines are available in sqlite_aux.h so that adaptors for
195** connecting SQLite to other operating systems can use the same byte
196** ranges for locking. In particular, the same locking strategy and
197** byte ranges are used for Unix. This leaves open the possiblity of having
198** clients on win95, winNT, and unix all talking to the same shared file
199** and all locking correctly. To do so would require that samba (or whatever
200** tool is being used for file sharing) implements locks correctly between
201** windows and unix. I'm guessing that isn't likely to happen, but by
202** using the same locking range we are at least open to the possibility.
203**
204** Locking in windows is manditory. For this reason, we cannot store
205** actual data in the bytes used for locking. The pager never allocates
206** the pages involved in locking therefore. SHARED_SIZE is selected so
207** that all locks will fit on a single page even at the minimum page size.
208** PENDING_BYTE defines the beginning of the locks. By default PENDING_BYTE
209** is set high so that we don't have to allocate an unused page except
210** for very large databases. But one should test the page skipping logic
211** by setting PENDING_BYTE low and running the entire regression suite.
212**
213** Changing the value of PENDING_BYTE results in a subtly incompatible
214** file format. Depending on how it is changed, you might not notice
215** the incompatibility right away, even running a full regression test.
216** The default location of PENDING_BYTE is the first byte past the
217** 1GB boundary.
218**
219*/
220#ifndef SQLITE_TEST
221#define PENDING_BYTE 0x40000000 /* First byte past the 1GB boundary */
222#else
223extern unsigned int sqlite3_pending_byte;
224#define PENDING_BYTE sqlite3_pending_byte
225#endif
226
227#define RESERVED_BYTE (PENDING_BYTE+1)
228#define SHARED_FIRST (PENDING_BYTE+2)
229#define SHARED_SIZE 510
230
231/*
232** Functions for accessing sqlite3_file methods
233*/
234int sqlite3OsClose(sqlite3_file*);
235int sqlite3OsRead(sqlite3_file*, void*, int amt, i64 offset);
236int sqlite3OsWrite(sqlite3_file*, const void*, int amt, i64 offset);
237int sqlite3OsTruncate(sqlite3_file*, i64 size);
238int sqlite3OsSync(sqlite3_file*, int);
239int sqlite3OsFileSize(sqlite3_file*, i64 *pSize);
240int sqlite3OsLock(sqlite3_file*, int);
241int sqlite3OsUnlock(sqlite3_file*, int);
242int sqlite3OsCheckReservedLock(sqlite3_file *id);
243int sqlite3OsFileControl(sqlite3_file*,int,void*);
244int sqlite3OsSectorSize(sqlite3_file *id);
245int sqlite3OsDeviceCharacteristics(sqlite3_file *id);
246
247/*
248** Functions for accessing sqlite3_vfs methods
249*/
250int sqlite3OsOpen(sqlite3_vfs *, const char *, sqlite3_file*, int, int *);
251int sqlite3OsDelete(sqlite3_vfs *, const char *, int);
252int sqlite3OsAccess(sqlite3_vfs *, const char *, int);
253int sqlite3OsGetTempname(sqlite3_vfs *, int, char *);
254int sqlite3OsFullPathname(sqlite3_vfs *, const char *, int, char *);
255void *sqlite3OsDlOpen(sqlite3_vfs *, const char *);
256void sqlite3OsDlError(sqlite3_vfs *, int, char *);
257void *sqlite3OsDlSym(sqlite3_vfs *, void *, const char *);
258void sqlite3OsDlClose(sqlite3_vfs *, void *);
259int sqlite3OsRandomness(sqlite3_vfs *, int, char *);
260int sqlite3OsSleep(sqlite3_vfs *, int);
261int sqlite3OsCurrentTime(sqlite3_vfs *, double*);
262
263/*
264** Convenience functions for opening and closing files using
265** sqlite3_malloc() to obtain space for the file-handle structure.
266*/
267int sqlite3OsOpenMalloc(sqlite3_vfs *, const char *, sqlite3_file **, int,int*);
268int sqlite3OsCloseFree(sqlite3_file *);
269
270/*
271** Each OS-specific backend defines an instance of the following
272** structure for returning a pointer to its sqlite3_vfs. If OS_OTHER
273** is defined (meaning that the application-defined OS interface layer
274** is used) then there is no default VFS. The application must
275** register one or more VFS structures using sqlite3_vfs_register()
276** before attempting to use SQLite.
277*/
278#if OS_UNIX || OS_WIN || OS_OS2
279sqlite3_vfs *sqlite3OsDefaultVfs(void);
280#else
281# define sqlite3OsDefaultVfs(X) 0
282#endif
283
284#endif /* _SQLITE_OS_H_ */