xref: /sqlite-3.40.0/src/global.c (revision f71a243a)
1 /*
2 ** 2008 June 13
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 file contains definitions of global variables and constants.
14 */
15 #include "sqliteInt.h"
16 
17 /* An array to map all upper-case characters into their corresponding
18 ** lower-case character.
19 **
20 ** SQLite only considers US-ASCII (or EBCDIC) characters.  We do not
21 ** handle case conversions for the UTF character set since the tables
22 ** involved are nearly as big or bigger than SQLite itself.
23 */
24 const unsigned char sqlite3UpperToLower[] = {
25 #ifdef SQLITE_ASCII
26       0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, 16, 17,
27      18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
28      36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
29      54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 97, 98, 99,100,101,102,103,
30     104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,
31     122, 91, 92, 93, 94, 95, 96, 97, 98, 99,100,101,102,103,104,105,106,107,
32     108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,
33     126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
34     144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,
35     162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,
36     180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,
37     198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,
38     216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,
39     234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,
40     252,253,254,255
41 #endif
42 #ifdef SQLITE_EBCDIC
43       0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, /* 0x */
44      16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, /* 1x */
45      32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, /* 2x */
46      48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, /* 3x */
47      64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, /* 4x */
48      80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, /* 5x */
49      96, 97, 98, 99,100,101,102,103,104,105,106,107,108,109,110,111, /* 6x */
50     112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127, /* 7x */
51     128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143, /* 8x */
52     144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159, /* 9x */
53     160,161,162,163,164,165,166,167,168,169,170,171,140,141,142,175, /* Ax */
54     176,177,178,179,180,181,182,183,184,185,186,187,188,189,190,191, /* Bx */
55     192,129,130,131,132,133,134,135,136,137,202,203,204,205,206,207, /* Cx */
56     208,145,146,147,148,149,150,151,152,153,218,219,220,221,222,223, /* Dx */
57     224,225,162,163,164,165,166,167,168,169,234,235,236,237,238,239, /* Ex */
58     240,241,242,243,244,245,246,247,248,249,250,251,252,253,254,255, /* Fx */
59 #endif
60 };
61 
62 /*
63 ** The following 256 byte lookup table is used to support SQLites built-in
64 ** equivalents to the following standard library functions:
65 **
66 **   isspace()                        0x01
67 **   isalpha()                        0x02
68 **   isdigit()                        0x04
69 **   isalnum()                        0x06
70 **   isxdigit()                       0x08
71 **   toupper()                        0x20
72 **   SQLite identifier character      0x40
73 **   Quote character                  0x80
74 **
75 ** Bit 0x20 is set if the mapped character requires translation to upper
76 ** case. i.e. if the character is a lower-case ASCII character.
77 ** If x is a lower-case ASCII character, then its upper-case equivalent
78 ** is (x - 0x20). Therefore toupper() can be implemented as:
79 **
80 **   (x & ~(map[x]&0x20))
81 **
82 ** The equivalent of tolower() is implemented using the sqlite3UpperToLower[]
83 ** array. tolower() is used more often than toupper() by SQLite.
84 **
85 ** Bit 0x40 is set if the character is non-alphanumeric and can be used in an
86 ** SQLite identifier.  Identifiers are alphanumerics, "_", "$", and any
87 ** non-ASCII UTF character. Hence the test for whether or not a character is
88 ** part of an identifier is 0x46.
89 */
90 #ifdef SQLITE_ASCII
91 const unsigned char sqlite3CtypeMap[256] = {
92   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 00..07    ........ */
93   0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00,  /* 08..0f    ........ */
94   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 10..17    ........ */
95   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 18..1f    ........ */
96   0x01, 0x00, 0x80, 0x00, 0x40, 0x00, 0x00, 0x80,  /* 20..27     !"#$%&' */
97   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 28..2f    ()*+,-./ */
98   0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,  /* 30..37    01234567 */
99   0x0c, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 38..3f    89:;<=>? */
100 
101   0x00, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x02,  /* 40..47    @ABCDEFG */
102   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 48..4f    HIJKLMNO */
103   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 50..57    PQRSTUVW */
104   0x02, 0x02, 0x02, 0x80, 0x00, 0x00, 0x00, 0x40,  /* 58..5f    XYZ[\]^_ */
105   0x80, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x22,  /* 60..67    `abcdefg */
106   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 68..6f    hijklmno */
107   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 70..77    pqrstuvw */
108   0x22, 0x22, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 78..7f    xyz{|}~. */
109 
110   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 80..87    ........ */
111   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 88..8f    ........ */
112   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 90..97    ........ */
113   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 98..9f    ........ */
114   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* a0..a7    ........ */
115   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* a8..af    ........ */
116   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* b0..b7    ........ */
117   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* b8..bf    ........ */
118 
119   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* c0..c7    ........ */
120   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* c8..cf    ........ */
121   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* d0..d7    ........ */
122   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* d8..df    ........ */
123   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* e0..e7    ........ */
124   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* e8..ef    ........ */
125   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* f0..f7    ........ */
126   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40   /* f8..ff    ........ */
127 };
128 #endif
129 
130 /* EVIDENCE-OF: R-02982-34736 In order to maintain full backwards
131 ** compatibility for legacy applications, the URI filename capability is
132 ** disabled by default.
133 **
134 ** EVIDENCE-OF: R-38799-08373 URI filenames can be enabled or disabled
135 ** using the SQLITE_USE_URI=1 or SQLITE_USE_URI=0 compile-time options.
136 **
137 ** EVIDENCE-OF: R-43642-56306 By default, URI handling is globally
138 ** disabled. The default value may be changed by compiling with the
139 ** SQLITE_USE_URI symbol defined.
140 **
141 ** URI filenames are enabled by default if SQLITE_HAS_CODEC is
142 ** enabled.
143 */
144 #ifndef SQLITE_USE_URI
145 # ifdef SQLITE_HAS_CODEC
146 #  define SQLITE_USE_URI 1
147 # else
148 #  define SQLITE_USE_URI 0
149 # endif
150 #endif
151 
152 /* EVIDENCE-OF: R-38720-18127 The default setting is determined by the
153 ** SQLITE_ALLOW_COVERING_INDEX_SCAN compile-time option, or is "on" if
154 ** that compile-time option is omitted.
155 */
156 #if !defined(SQLITE_ALLOW_COVERING_INDEX_SCAN)
157 # define SQLITE_ALLOW_COVERING_INDEX_SCAN 1
158 #else
159 # if !SQLITE_ALLOW_COVERING_INDEX_SCAN
160 #   error "Compile-time disabling of covering index scan using the\
161  -DSQLITE_ALLOW_COVERING_INDEX_SCAN=0 option is deprecated.\
162  Contact SQLite developers if this is a problem for you, and\
163  delete this #error macro to continue with your build."
164 # endif
165 #endif
166 
167 /* The minimum PMA size is set to this value multiplied by the database
168 ** page size in bytes.
169 */
170 #ifndef SQLITE_SORTER_PMASZ
171 # define SQLITE_SORTER_PMASZ 250
172 #endif
173 
174 /* Statement journals spill to disk when their size exceeds the following
175 ** threshold (in bytes). 0 means that statement journals are created and
176 ** written to disk immediately (the default behavior for SQLite versions
177 ** before 3.12.0).  -1 means always keep the entire statement journal in
178 ** memory.  (The statement journal is also always held entirely in memory
179 ** if journal_mode=MEMORY or if temp_store=MEMORY, regardless of this
180 ** setting.)
181 */
182 #ifndef SQLITE_STMTJRNL_SPILL
183 # define SQLITE_STMTJRNL_SPILL (64*1024)
184 #endif
185 
186 /*
187 ** The default lookaside-configuration, the format "SZ,N".  SZ is the
188 ** number of bytes in each lookaside slot (should be a multiple of 8)
189 ** and N is the number of slots.  The lookaside-configuration can be
190 ** changed as start-time using sqlite3_config(SQLITE_CONFIG_LOOKASIDE)
191 ** or at run-time for an individual database connection using
192 ** sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE);
193 */
194 #ifndef SQLITE_DEFAULT_LOOKASIDE
195 # define SQLITE_DEFAULT_LOOKASIDE 1200,100
196 #endif
197 
198 
199 /* The default maximum size of an in-memory database created using
200 ** sqlite3_deserialize()
201 */
202 #ifndef SQLITE_MEMDB_DEFAULT_MAXSIZE
203 # define SQLITE_MEMDB_DEFAULT_MAXSIZE 1073741824
204 #endif
205 
206 /*
207 ** The following singleton contains the global configuration for
208 ** the SQLite library.
209 */
210 SQLITE_WSD struct Sqlite3Config sqlite3Config = {
211    SQLITE_DEFAULT_MEMSTATUS,  /* bMemstat */
212    1,                         /* bCoreMutex */
213    SQLITE_THREADSAFE==1,      /* bFullMutex */
214    SQLITE_USE_URI,            /* bOpenUri */
215    SQLITE_ALLOW_COVERING_INDEX_SCAN,   /* bUseCis */
216    0,                         /* bSmallMalloc */
217    0x7ffffffe,                /* mxStrlen */
218    0,                         /* neverCorrupt */
219    SQLITE_DEFAULT_LOOKASIDE,  /* szLookaside, nLookaside */
220    SQLITE_STMTJRNL_SPILL,     /* nStmtSpill */
221    {0,0,0,0,0,0,0,0},         /* m */
222    {0,0,0,0,0,0,0,0,0},       /* mutex */
223    {0,0,0,0,0,0,0,0,0,0,0,0,0},/* pcache2 */
224    (void*)0,                  /* pHeap */
225    0,                         /* nHeap */
226    0, 0,                      /* mnHeap, mxHeap */
227    SQLITE_DEFAULT_MMAP_SIZE,  /* szMmap */
228    SQLITE_MAX_MMAP_SIZE,      /* mxMmap */
229    (void*)0,                  /* pPage */
230    0,                         /* szPage */
231    SQLITE_DEFAULT_PCACHE_INITSZ, /* nPage */
232    0,                         /* mxParserStack */
233    0,                         /* sharedCacheEnabled */
234    SQLITE_SORTER_PMASZ,       /* szPma */
235    /* All the rest should always be initialized to zero */
236    0,                         /* isInit */
237    0,                         /* inProgress */
238    0,                         /* isMutexInit */
239    0,                         /* isMallocInit */
240    0,                         /* isPCacheInit */
241    0,                         /* nRefInitMutex */
242    0,                         /* pInitMutex */
243    0,                         /* xLog */
244    0,                         /* pLogArg */
245 #ifdef SQLITE_ENABLE_SQLLOG
246    0,                         /* xSqllog */
247    0,                         /* pSqllogArg */
248 #endif
249 #ifdef SQLITE_VDBE_COVERAGE
250    0,                         /* xVdbeBranch */
251    0,                         /* pVbeBranchArg */
252 #endif
253 #ifdef SQLITE_ENABLE_DESERIALIZE
254    SQLITE_MEMDB_DEFAULT_MAXSIZE,   /* mxMemdbSize */
255 #endif
256 #ifndef SQLITE_UNTESTABLE
257    0,                         /* xTestCallback */
258 #endif
259    0,                         /* bLocaltimeFault */
260    0,                         /* bInternalFunctions */
261    0x7ffffffe,                /* iOnceResetThreshold */
262    SQLITE_DEFAULT_SORTERREF_SIZE,   /* szSorterRef */
263 };
264 
265 /*
266 ** Hash table for global functions - functions common to all
267 ** database connections.  After initialization, this table is
268 ** read-only.
269 */
270 FuncDefHash sqlite3BuiltinFunctions;
271 
272 /*
273 ** Constant tokens for values 0 and 1.
274 */
275 const Token sqlite3IntTokens[] = {
276    { "0", 1 },
277    { "1", 1 }
278 };
279 
280 #ifdef VDBE_PROFILE
281 /*
282 ** The following performance counter can be used in place of
283 ** sqlite3Hwtime() for profiling.  This is a no-op on standard builds.
284 */
285 sqlite3_uint64 sqlite3NProfileCnt = 0;
286 #endif
287 
288 /*
289 ** The value of the "pending" byte must be 0x40000000 (1 byte past the
290 ** 1-gibabyte boundary) in a compatible database.  SQLite never uses
291 ** the database page that contains the pending byte.  It never attempts
292 ** to read or write that page.  The pending byte page is set aside
293 ** for use by the VFS layers as space for managing file locks.
294 **
295 ** During testing, it is often desirable to move the pending byte to
296 ** a different position in the file.  This allows code that has to
297 ** deal with the pending byte to run on files that are much smaller
298 ** than 1 GiB.  The sqlite3_test_control() interface can be used to
299 ** move the pending byte.
300 **
301 ** IMPORTANT:  Changing the pending byte to any value other than
302 ** 0x40000000 results in an incompatible database file format!
303 ** Changing the pending byte during operation will result in undefined
304 ** and incorrect behavior.
305 */
306 #ifndef SQLITE_OMIT_WSD
307 int sqlite3PendingByte = 0x40000000;
308 #endif
309 
310 #include "opcodes.h"
311 /*
312 ** Properties of opcodes.  The OPFLG_INITIALIZER macro is
313 ** created by mkopcodeh.awk during compilation.  Data is obtained
314 ** from the comments following the "case OP_xxxx:" statements in
315 ** the vdbe.c file.
316 */
317 const unsigned char sqlite3OpcodeProperty[] = OPFLG_INITIALIZER;
318 
319 /*
320 ** Name of the default collating sequence
321 */
322 const char sqlite3StrBINARY[] = "BINARY";
323