xref: /sqlite-3.40.0/src/global.c (revision 705d7be6)
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 /* All of the upper-to-lower conversion data is above.  The following
61 ** 18 integers are completely unrelated.  They are appended to the
62 ** sqlite3UpperToLower[] array to avoid UBSAN warnings.  Here's what is
63 ** going on:
64 **
65 ** The SQL comparison operators (<>, =, >, <=, <, and >=) are implemented
66 ** by invoking sqlite3MemCompare(A,B) which compares values A and B and
67 ** returns negative, zero, or positive if A is less then, equal to, or
68 ** greater than B, respectively.  Then the true false results is found by
69 ** consulting sqlite3aLTb[opcode], sqlite3aEQb[opcode], or
70 ** sqlite3aGTb[opcode] depending on whether the result of compare(A,B)
71 ** is negative, zero, or positive, where opcode is the specific opcode.
72 ** The only works because the comparison opcodes are consecutive and in
73 ** this order: NE EQ GT LE LT GE.  Various assert()s throughout the code
74 ** ensure that is the case.
75 **
76 ** These elements must be appended to another array.  Otherwise the
77 ** index (here shown as [256-OP_Ne]) would be out-of-bounds and thus
78 ** be undefined behavior.  That's goofy, but the C-standards people thought
79 ** it was a good idea, so here we are.
80 */
81 /* NE  EQ  GT  LE  LT  GE  */
82    1,  0,  0,  1,  1,  0,  /* aLTb[]: Use when compare(A,B) less than zero */
83    0,  1,  0,  1,  0,  1,  /* aEQb[]: Use when compare(A,B) equals zero */
84    1,  0,  1,  0,  0,  1   /* aGTb[]: Use when compare(A,B) greater than zero*/
85 };
86 const unsigned char *sqlite3aLTb = &sqlite3UpperToLower[256-OP_Ne];
87 const unsigned char *sqlite3aEQb = &sqlite3UpperToLower[256+6-OP_Ne];
88 const unsigned char *sqlite3aGTb = &sqlite3UpperToLower[256+12-OP_Ne];
89 
90 /*
91 ** The following 256 byte lookup table is used to support SQLites built-in
92 ** equivalents to the following standard library functions:
93 **
94 **   isspace()                        0x01
95 **   isalpha()                        0x02
96 **   isdigit()                        0x04
97 **   isalnum()                        0x06
98 **   isxdigit()                       0x08
99 **   toupper()                        0x20
100 **   SQLite identifier character      0x40
101 **   Quote character                  0x80
102 **
103 ** Bit 0x20 is set if the mapped character requires translation to upper
104 ** case. i.e. if the character is a lower-case ASCII character.
105 ** If x is a lower-case ASCII character, then its upper-case equivalent
106 ** is (x - 0x20). Therefore toupper() can be implemented as:
107 **
108 **   (x & ~(map[x]&0x20))
109 **
110 ** The equivalent of tolower() is implemented using the sqlite3UpperToLower[]
111 ** array. tolower() is used more often than toupper() by SQLite.
112 **
113 ** Bit 0x40 is set if the character is non-alphanumeric and can be used in an
114 ** SQLite identifier.  Identifiers are alphanumerics, "_", "$", and any
115 ** non-ASCII UTF character. Hence the test for whether or not a character is
116 ** part of an identifier is 0x46.
117 */
118 const unsigned char sqlite3CtypeMap[256] = {
119   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 00..07    ........ */
120   0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00, 0x00,  /* 08..0f    ........ */
121   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 10..17    ........ */
122   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 18..1f    ........ */
123   0x01, 0x00, 0x80, 0x00, 0x40, 0x00, 0x00, 0x80,  /* 20..27     !"#$%&' */
124   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 28..2f    ()*+,-./ */
125   0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,  /* 30..37    01234567 */
126   0x0c, 0x0c, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 38..3f    89:;<=>? */
127 
128   0x00, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x02,  /* 40..47    @ABCDEFG */
129   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 48..4f    HIJKLMNO */
130   0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,  /* 50..57    PQRSTUVW */
131   0x02, 0x02, 0x02, 0x80, 0x00, 0x00, 0x00, 0x40,  /* 58..5f    XYZ[\]^_ */
132   0x80, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x22,  /* 60..67    `abcdefg */
133   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 68..6f    hijklmno */
134   0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,  /* 70..77    pqrstuvw */
135   0x22, 0x22, 0x22, 0x00, 0x00, 0x00, 0x00, 0x00,  /* 78..7f    xyz{|}~. */
136 
137   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 80..87    ........ */
138   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 88..8f    ........ */
139   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 90..97    ........ */
140   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* 98..9f    ........ */
141   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* a0..a7    ........ */
142   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* a8..af    ........ */
143   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* b0..b7    ........ */
144   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* b8..bf    ........ */
145 
146   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* c0..c7    ........ */
147   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* c8..cf    ........ */
148   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* d0..d7    ........ */
149   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* d8..df    ........ */
150   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* e0..e7    ........ */
151   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* e8..ef    ........ */
152   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40,  /* f0..f7    ........ */
153   0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40   /* f8..ff    ........ */
154 };
155 
156 /* EVIDENCE-OF: R-02982-34736 In order to maintain full backwards
157 ** compatibility for legacy applications, the URI filename capability is
158 ** disabled by default.
159 **
160 ** EVIDENCE-OF: R-38799-08373 URI filenames can be enabled or disabled
161 ** using the SQLITE_USE_URI=1 or SQLITE_USE_URI=0 compile-time options.
162 **
163 ** EVIDENCE-OF: R-43642-56306 By default, URI handling is globally
164 ** disabled. The default value may be changed by compiling with the
165 ** SQLITE_USE_URI symbol defined.
166 */
167 #ifndef SQLITE_USE_URI
168 # define SQLITE_USE_URI 0
169 #endif
170 
171 /* EVIDENCE-OF: R-38720-18127 The default setting is determined by the
172 ** SQLITE_ALLOW_COVERING_INDEX_SCAN compile-time option, or is "on" if
173 ** that compile-time option is omitted.
174 */
175 #if !defined(SQLITE_ALLOW_COVERING_INDEX_SCAN)
176 # define SQLITE_ALLOW_COVERING_INDEX_SCAN 1
177 #else
178 # if !SQLITE_ALLOW_COVERING_INDEX_SCAN
179 #   error "Compile-time disabling of covering index scan using the\
180  -DSQLITE_ALLOW_COVERING_INDEX_SCAN=0 option is deprecated.\
181  Contact SQLite developers if this is a problem for you, and\
182  delete this #error macro to continue with your build."
183 # endif
184 #endif
185 
186 /* The minimum PMA size is set to this value multiplied by the database
187 ** page size in bytes.
188 */
189 #ifndef SQLITE_SORTER_PMASZ
190 # define SQLITE_SORTER_PMASZ 250
191 #endif
192 
193 /* Statement journals spill to disk when their size exceeds the following
194 ** threshold (in bytes). 0 means that statement journals are created and
195 ** written to disk immediately (the default behavior for SQLite versions
196 ** before 3.12.0).  -1 means always keep the entire statement journal in
197 ** memory.  (The statement journal is also always held entirely in memory
198 ** if journal_mode=MEMORY or if temp_store=MEMORY, regardless of this
199 ** setting.)
200 */
201 #ifndef SQLITE_STMTJRNL_SPILL
202 # define SQLITE_STMTJRNL_SPILL (64*1024)
203 #endif
204 
205 /*
206 ** The default lookaside-configuration, the format "SZ,N".  SZ is the
207 ** number of bytes in each lookaside slot (should be a multiple of 8)
208 ** and N is the number of slots.  The lookaside-configuration can be
209 ** changed as start-time using sqlite3_config(SQLITE_CONFIG_LOOKASIDE)
210 ** or at run-time for an individual database connection using
211 ** sqlite3_db_config(db, SQLITE_DBCONFIG_LOOKASIDE);
212 **
213 ** With the two-size-lookaside enhancement, less lookaside is required.
214 ** The default configuration of 1200,40 actually provides 30 1200-byte slots
215 ** and 93 128-byte slots, which is more lookaside than is available
216 ** using the older 1200,100 configuration without two-size-lookaside.
217 */
218 #ifndef SQLITE_DEFAULT_LOOKASIDE
219 # ifdef SQLITE_OMIT_TWOSIZE_LOOKASIDE
220 #   define SQLITE_DEFAULT_LOOKASIDE 1200,100  /* 120KB of memory */
221 # else
222 #   define SQLITE_DEFAULT_LOOKASIDE 1200,40   /* 48KB of memory */
223 # endif
224 #endif
225 
226 
227 /* The default maximum size of an in-memory database created using
228 ** sqlite3_deserialize()
229 */
230 #ifndef SQLITE_MEMDB_DEFAULT_MAXSIZE
231 # define SQLITE_MEMDB_DEFAULT_MAXSIZE 1073741824
232 #endif
233 
234 /*
235 ** The following singleton contains the global configuration for
236 ** the SQLite library.
237 */
238 SQLITE_WSD struct Sqlite3Config sqlite3Config = {
239    SQLITE_DEFAULT_MEMSTATUS,  /* bMemstat */
240    1,                         /* bCoreMutex */
241    SQLITE_THREADSAFE==1,      /* bFullMutex */
242    SQLITE_USE_URI,            /* bOpenUri */
243    SQLITE_ALLOW_COVERING_INDEX_SCAN,   /* bUseCis */
244    0,                         /* bSmallMalloc */
245    1,                         /* bExtraSchemaChecks */
246    0x7ffffffe,                /* mxStrlen */
247    0,                         /* neverCorrupt */
248    SQLITE_DEFAULT_LOOKASIDE,  /* szLookaside, nLookaside */
249    SQLITE_STMTJRNL_SPILL,     /* nStmtSpill */
250    {0,0,0,0,0,0,0,0},         /* m */
251    {0,0,0,0,0,0,0,0,0},       /* mutex */
252    {0,0,0,0,0,0,0,0,0,0,0,0,0},/* pcache2 */
253    (void*)0,                  /* pHeap */
254    0,                         /* nHeap */
255    0, 0,                      /* mnHeap, mxHeap */
256    SQLITE_DEFAULT_MMAP_SIZE,  /* szMmap */
257    SQLITE_MAX_MMAP_SIZE,      /* mxMmap */
258    (void*)0,                  /* pPage */
259    0,                         /* szPage */
260    SQLITE_DEFAULT_PCACHE_INITSZ, /* nPage */
261    0,                         /* mxParserStack */
262    0,                         /* sharedCacheEnabled */
263    SQLITE_SORTER_PMASZ,       /* szPma */
264    /* All the rest should always be initialized to zero */
265    0,                         /* isInit */
266    0,                         /* inProgress */
267    0,                         /* isMutexInit */
268    0,                         /* isMallocInit */
269    0,                         /* isPCacheInit */
270    0,                         /* nRefInitMutex */
271    0,                         /* pInitMutex */
272    0,                         /* xLog */
273    0,                         /* pLogArg */
274 #ifdef SQLITE_ENABLE_SQLLOG
275    0,                         /* xSqllog */
276    0,                         /* pSqllogArg */
277 #endif
278 #ifdef SQLITE_VDBE_COVERAGE
279    0,                         /* xVdbeBranch */
280    0,                         /* pVbeBranchArg */
281 #endif
282 #ifndef SQLITE_OMIT_DESERIALIZE
283    SQLITE_MEMDB_DEFAULT_MAXSIZE,   /* mxMemdbSize */
284 #endif
285 #ifndef SQLITE_UNTESTABLE
286    0,                         /* xTestCallback */
287 #endif
288    0,                         /* bLocaltimeFault */
289    0,                         /* xAltLocaltime */
290    0x7ffffffe,                /* iOnceResetThreshold */
291    SQLITE_DEFAULT_SORTERREF_SIZE,   /* szSorterRef */
292    0,                         /* iPrngSeed */
293 #ifdef SQLITE_DEBUG
294    {0,0,0,0,0,0}              /* aTune */
295 #endif
296 };
297 
298 /*
299 ** Hash table for global functions - functions common to all
300 ** database connections.  After initialization, this table is
301 ** read-only.
302 */
303 FuncDefHash sqlite3BuiltinFunctions;
304 
305 #if defined(SQLITE_COVERAGE_TEST) || defined(SQLITE_DEBUG)
306 /*
307 ** Counter used for coverage testing.  Does not come into play for
308 ** release builds.
309 **
310 ** Access to this global variable is not mutex protected.  This might
311 ** result in TSAN warnings.  But as the variable does not exist in
312 ** release builds, that should not be a concern.
313 */
314 unsigned int sqlite3CoverageCounter;
315 #endif /* SQLITE_COVERAGE_TEST || SQLITE_DEBUG */
316 
317 #ifdef VDBE_PROFILE
318 /*
319 ** The following performance counter can be used in place of
320 ** sqlite3Hwtime() for profiling.  This is a no-op on standard builds.
321 */
322 sqlite3_uint64 sqlite3NProfileCnt = 0;
323 #endif
324 
325 /*
326 ** The value of the "pending" byte must be 0x40000000 (1 byte past the
327 ** 1-gibabyte boundary) in a compatible database.  SQLite never uses
328 ** the database page that contains the pending byte.  It never attempts
329 ** to read or write that page.  The pending byte page is set aside
330 ** for use by the VFS layers as space for managing file locks.
331 **
332 ** During testing, it is often desirable to move the pending byte to
333 ** a different position in the file.  This allows code that has to
334 ** deal with the pending byte to run on files that are much smaller
335 ** than 1 GiB.  The sqlite3_test_control() interface can be used to
336 ** move the pending byte.
337 **
338 ** IMPORTANT:  Changing the pending byte to any value other than
339 ** 0x40000000 results in an incompatible database file format!
340 ** Changing the pending byte during operation will result in undefined
341 ** and incorrect behavior.
342 */
343 #ifndef SQLITE_OMIT_WSD
344 int sqlite3PendingByte = 0x40000000;
345 #endif
346 
347 /*
348 ** Tracing flags set by SQLITE_TESTCTRL_TRACEFLAGS.
349 */
350 u32 sqlite3TreeTrace = 0;
351 u32 sqlite3WhereTrace = 0;
352 
353 #include "opcodes.h"
354 /*
355 ** Properties of opcodes.  The OPFLG_INITIALIZER macro is
356 ** created by mkopcodeh.awk during compilation.  Data is obtained
357 ** from the comments following the "case OP_xxxx:" statements in
358 ** the vdbe.c file.
359 */
360 const unsigned char sqlite3OpcodeProperty[] = OPFLG_INITIALIZER;
361 
362 /*
363 ** Name of the default collating sequence
364 */
365 const char sqlite3StrBINARY[] = "BINARY";
366 
367 /*
368 ** Standard typenames.  These names must match the COLTYPE_* definitions.
369 ** Adjust the SQLITE_N_STDTYPE value if adding or removing entries.
370 **
371 **    sqlite3StdType[]            The actual names of the datatypes.
372 **
373 **    sqlite3StdTypeLen[]         The length (in bytes) of each entry
374 **                                in sqlite3StdType[].
375 **
376 **    sqlite3StdTypeAffinity[]    The affinity associated with each entry
377 **                                in sqlite3StdType[].
378 */
379 const unsigned char sqlite3StdTypeLen[] = { 3, 4, 3, 7, 4, 4 };
380 const char sqlite3StdTypeAffinity[] = {
381   SQLITE_AFF_NUMERIC,
382   SQLITE_AFF_BLOB,
383   SQLITE_AFF_INTEGER,
384   SQLITE_AFF_INTEGER,
385   SQLITE_AFF_REAL,
386   SQLITE_AFF_TEXT
387 };
388 const char *sqlite3StdType[] = {
389   "ANY",
390   "BLOB",
391   "INT",
392   "INTEGER",
393   "REAL",
394   "TEXT"
395 };
396