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1 /* |
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2 ** 2001 September 15 |
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3 ** |
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4 ** The author disclaims copyright to this source code. In place of |
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5 ** a legal notice, here is a blessing: |
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6 ** |
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7 ** May you do good and not evil. |
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8 ** May you find forgiveness for yourself and forgive others. |
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9 ** May you share freely, never taking more than you give. |
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10 ** |
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11 ************************************************************************* |
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12 ** Header file for the Virtual DataBase Engine (VDBE) |
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13 ** |
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14 ** This header defines the interface to the virtual database engine |
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15 ** or VDBE. The VDBE implements an abstract machine that runs a |
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16 ** simple program to access and modify the underlying database. |
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17 ** |
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18 ** $Id: vdbe.h,v 1.105 2006/06/13 23:51:35 drh Exp $ |
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19 */ |
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20 #ifndef _SQLITE_VDBE_H_ |
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21 #define _SQLITE_VDBE_H_ |
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22 #include <stdio.h> |
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23 |
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24 /* |
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25 ** A single VDBE is an opaque structure named "Vdbe". Only routines |
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26 ** in the source file sqliteVdbe.c are allowed to see the insides |
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27 ** of this structure. |
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28 */ |
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29 typedef struct Vdbe Vdbe; |
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30 |
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31 /* |
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32 ** A single instruction of the virtual machine has an opcode |
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33 ** and as many as three operands. The instruction is recorded |
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34 ** as an instance of the following structure: |
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35 */ |
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36 struct VdbeOp { |
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37 u8 opcode; /* What operation to perform */ |
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38 int p1; /* First operand */ |
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39 int p2; /* Second parameter (often the jump destination) */ |
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40 char *p3; /* Third parameter */ |
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41 int p3type; /* One of the P3_xxx constants defined below */ |
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42 #ifdef VDBE_PROFILE |
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43 int cnt; /* Number of times this instruction was executed */ |
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44 long long cycles; /* Total time spend executing this instruction */ |
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45 #endif |
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46 }; |
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47 typedef struct VdbeOp VdbeOp; |
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48 |
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49 /* |
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50 ** A smaller version of VdbeOp used for the VdbeAddOpList() function because |
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51 ** it takes up less space. |
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52 */ |
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53 struct VdbeOpList { |
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54 u8 opcode; /* What operation to perform */ |
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55 signed char p1; /* First operand */ |
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56 short int p2; /* Second parameter (often the jump destination) */ |
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57 char *p3; /* Third parameter */ |
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58 }; |
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59 typedef struct VdbeOpList VdbeOpList; |
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60 |
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61 /* |
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62 ** Allowed values of VdbeOp.p3type |
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63 */ |
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64 #define P3_NOTUSED 0 /* The P3 parameter is not used */ |
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65 #define P3_DYNAMIC (-1) /* Pointer to a string obtained from sqliteMalloc() */ |
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66 #define P3_STATIC (-2) /* Pointer to a static string */ |
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67 #define P3_COLLSEQ (-4) /* P3 is a pointer to a CollSeq structure */ |
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68 #define P3_FUNCDEF (-5) /* P3 is a pointer to a FuncDef structure */ |
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69 #define P3_KEYINFO (-6) /* P3 is a pointer to a KeyInfo structure */ |
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70 #define P3_VDBEFUNC (-7) /* P3 is a pointer to a VdbeFunc structure */ |
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71 #define P3_MEM (-8) /* P3 is a pointer to a Mem* structure */ |
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72 #define P3_TRANSIENT (-9) /* P3 is a pointer to a transient string */ |
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73 #define P3_VTAB (-10) /* P3 is a pointer to an sqlite3_vtab structure */ |
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74 #define P3_MPRINTF (-11) /* P3 is a string obtained from sqlite3_mprintf() */ |
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75 |
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76 /* When adding a P3 argument using P3_KEYINFO, a copy of the KeyInfo structure |
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77 ** is made. That copy is freed when the Vdbe is finalized. But if the |
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78 ** argument is P3_KEYINFO_HANDOFF, the passed in pointer is used. It still |
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79 ** gets freed when the Vdbe is finalized so it still should be obtained |
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80 ** from a single sqliteMalloc(). But no copy is made and the calling |
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81 ** function should *not* try to free the KeyInfo. |
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82 */ |
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83 #define P3_KEYINFO_HANDOFF (-9) |
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84 |
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85 /* |
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86 ** The Vdbe.aColName array contains 5n Mem structures, where n is the |
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87 ** number of columns of data returned by the statement. |
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88 */ |
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89 #define COLNAME_NAME 0 |
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90 #define COLNAME_DECLTYPE 1 |
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91 #define COLNAME_DATABASE 2 |
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92 #define COLNAME_TABLE 3 |
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93 #define COLNAME_COLUMN 4 |
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94 #define COLNAME_N 5 /* Number of COLNAME_xxx symbols */ |
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95 |
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96 /* |
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97 ** The following macro converts a relative address in the p2 field |
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98 ** of a VdbeOp structure into a negative number so that |
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99 ** sqlite3VdbeAddOpList() knows that the address is relative. Calling |
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100 ** the macro again restores the address. |
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101 */ |
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102 #define ADDR(X) (-1-(X)) |
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103 |
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104 /* |
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105 ** The makefile scans the vdbe.c source file and creates the "opcodes.h" |
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106 ** header file that defines a number for each opcode used by the VDBE. |
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107 */ |
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108 #include "opcodes.h" |
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109 |
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110 /* |
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111 ** Prototypes for the VDBE interface. See comments on the implementation |
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112 ** for a description of what each of these routines does. |
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113 */ |
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114 Vdbe *sqlite3VdbeCreate(sqlite3*); |
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115 void sqlite3VdbeCreateCallback(Vdbe*, int*); |
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116 int sqlite3VdbeAddOp(Vdbe*,int,int,int); |
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117 int sqlite3VdbeOp3(Vdbe*,int,int,int,const char *zP3,int); |
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118 int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp); |
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119 void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1); |
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120 void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2); |
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121 void sqlite3VdbeJumpHere(Vdbe*, int addr); |
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122 void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N); |
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123 void sqlite3VdbeChangeP3(Vdbe*, int addr, const char *zP1, int N); |
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124 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int); |
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125 int sqlite3VdbeMakeLabel(Vdbe*); |
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126 void sqlite3VdbeDelete(Vdbe*); |
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127 void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int); |
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128 int sqlite3VdbeFinalize(Vdbe*); |
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129 void sqlite3VdbeResolveLabel(Vdbe*, int); |
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130 int sqlite3VdbeCurrentAddr(Vdbe*); |
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131 void sqlite3VdbeTrace(Vdbe*,FILE*); |
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132 int sqlite3VdbeReset(Vdbe*); |
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133 int sqliteVdbeSetVariables(Vdbe*,int,const char**); |
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134 void sqlite3VdbeSetNumCols(Vdbe*,int); |
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135 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, int); |
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136 void sqlite3VdbeCountChanges(Vdbe*); |
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137 sqlite3 *sqlite3VdbeDb(Vdbe*); |
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138 |
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139 #ifndef NDEBUG |
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140 void sqlite3VdbeComment(Vdbe*, const char*, ...); |
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141 # define VdbeComment(X) sqlite3VdbeComment X |
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142 #else |
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143 # define VdbeComment(X) |
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144 #endif |
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145 |
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146 #endif |