Merge enhancements from trunk.

FossilOrigin-Name: 091403a6705f5f1352c76eacbfdca75fe0bab12ab9b156842641de07c38d3f66

1 files changed, 91 insertions, 14 deletions

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index d0452f548..b0b1658f1 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1298,6 +1298,25 @@ struct Schema {
 ** disables lookaside without adding a new test for the bDisable flag
 ** in a performance-critical path.  sz should be set by to szTrue whenever
 ** bDisable changes back to zero.
+**
+** Lookaside buffers are initially held on the pInit list.  As they are
+** used and freed, they are added back to the pFree list.  New allocations
+** come off of pFree first, then pInit as a fallback.  This dual-list
+** allows use to compute a high-water mark - the maximum number of allocations
+** outstanding at any point in the past - by subtracting the number of
+** allocations on the pInit list from the total number of allocations.
+**
+** Enhancement on 2019-12-12:  Two-size-lookaside
+** The default lookaside configuration is 100 slots of 1200 bytes each.
+** The larger slot sizes are important for performance, but they waste
+** a lot of space, as most lookaside allocations are less than 128 bytes.
+** The two-size-lookaside enhancement breaks up the lookaside allocation
+** into two pools:  One of 128-byte slots and the other of the default size
+** (1200-byte) slots.   Allocations are filled from the small-pool first,
+** failing over to the full-size pool if that does not work.  Thus more
+** lookaside slots are available while also using less memory.
+** This enhancement can be omitted by compiling with
+** SQLITE_OMIT_TWOSIZE_LOOKASIDE.
 */
 struct Lookaside {
   u32 bDisable;           /* Only operate the lookaside when zero */
@@ -1308,6 +1327,12 @@ struct Lookaside {
   u32 anStat[3];          /* 0: hits.  1: size misses.  2: full misses */
   LookasideSlot *pInit;   /* List of buffers not previously used */
   LookasideSlot *pFree;   /* List of available buffers */
+#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
+  LookasideSlot *pSmallInit; /* List of small buffers not prediously used */
+  LookasideSlot *pSmallFree; /* List of available small buffers */
+  void *pMiddle;          /* First byte past end of full-size buffers and
+                          ** the first byte of LOOKASIDE_SMALL buffers */
+#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
   void *pStart;           /* First byte of available memory space */
   void *pEnd;             /* First byte past end of available space */
 };
@@ -1319,6 +1344,13 @@ struct LookasideSlot {
 #define EnableLookaside   db->lookaside.bDisable--;\
    db->lookaside.sz=db->lookaside.bDisable?0:db->lookaside.szTrue
 
+/* Size of the smaller allocations in two-size lookside */
+#ifdef SQLITE_OMIT_TWOSIZE_LOOKASIDE
+#  define LOOKASIDE_SMALL           0
+#else
+#  define LOOKASIDE_SMALL         128
+#endif
+
 /*
 ** A hash table for built-in function definitions.  (Application-defined
 ** functions use a regular table table from hash.h.)
@@ -1600,6 +1632,7 @@ struct sqlite3 {
 #define DBFLAG_Vacuum         0x0004  /* Currently in a VACUUM */
 #define DBFLAG_VacuumInto     0x0008  /* Currently running VACUUM INTO */
 #define DBFLAG_SchemaKnownOk  0x0010  /* Schema is known to be valid */
+#define DBFLAG_InternalFunc   0x0020  /* Allow use of internal functions */
 
 /*
 ** Bits of the sqlite3.dbOptFlags field that are used by the
@@ -1723,12 +1756,21 @@ struct FuncDestructor {
 #define SQLITE_FUNC_MINMAX   0x1000 /* True for min() and max() aggregates */
 #define SQLITE_FUNC_SLOCHNG  0x2000 /* "Slow Change". Value constant during a
                                     ** single query - might change over time */
-#define SQLITE_FUNC_AFFINITY 0x4000 /* Built-in affinity() function */
+#define SQLITE_FUNC_TEST     0x4000 /* Built-in testing functions */
 #define SQLITE_FUNC_OFFSET   0x8000 /* Built-in sqlite_offset() function */
 #define SQLITE_FUNC_WINDOW   0x00010000 /* Built-in window-only function */
 #define SQLITE_FUNC_INTERNAL 0x00040000 /* For use by NestedParse() only */
 #define SQLITE_FUNC_DIRECT   0x00080000 /* Not for use in TRIGGERs or VIEWs */
 #define SQLITE_FUNC_SUBTYPE  0x00100000 /* Result likely to have sub-type */
+#define SQLITE_FUNC_INLINE   0x00200000 /* Functions implemented in-line */
+
+/* Identifier numbers for each in-line function */
+#define INLINEFUNC_coalesce             0
+#define INLINEFUNC_implies_nonnull_row  1
+#define INLINEFUNC_expr_implies_expr    2
+#define INLINEFUNC_expr_compare         3      
+#define INLINEFUNC_affinity             4
+#define INLINEFUNC_unlikely            99  /* Default case */
 
 /*
 ** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
@@ -1748,6 +1790,18 @@ struct FuncDestructor {
 **     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and
 **     adds the SQLITE_DIRECTONLY flag.
 **
+**   INLINE_FUNC(zName, nArg, iFuncId, mFlags)
+**     zName is the name of a function that is implemented by in-line
+**     byte code rather than by the usual callbacks. The iFuncId
+**     parameter determines the function id.  The mFlags parameter is
+**     optional SQLITE_FUNC_ flags for this function.
+**
+**   TEST_FUNC(zName, nArg, iFuncId, mFlags)
+**     zName is the name of a test-only function implemented by in-line
+**     byte code rather than by the usual callbacks. The iFuncId
+**     parameter determines the function id.  The mFlags parameter is
+**     optional SQLITE_FUNC_ flags for this function.
+**
 **   DFUNCTION(zName, nArg, iArg, bNC, xFunc)
 **     Like FUNCTION except it omits the SQLITE_FUNC_CONSTANT flag and
 **     adds the SQLITE_FUNC_SLOCHNG flag.  Used for date & time functions
@@ -1790,6 +1844,13 @@ struct FuncDestructor {
 #define SFUNCTION(zName, nArg, iArg, bNC, xFunc) \
   {nArg, SQLITE_UTF8|SQLITE_DIRECTONLY, \
    SQLITE_INT_TO_PTR(iArg), 0, xFunc, 0, 0, 0, #zName, {0} }
+#define INLINE_FUNC(zName, nArg, iArg, mFlags) \
+  {nArg, SQLITE_UTF8|SQLITE_FUNC_INLINE|SQLITE_FUNC_CONSTANT|(mFlags), \
+   SQLITE_INT_TO_PTR(iArg), 0, noopFunc, 0, 0, 0, #zName, {0} }
+#define TEST_FUNC(zName, nArg, iArg, mFlags) \
+  {nArg, SQLITE_UTF8|SQLITE_FUNC_INTERNAL|SQLITE_FUNC_TEST| \
+         SQLITE_FUNC_INLINE|SQLITE_FUNC_CONSTANT|(mFlags), \
+   SQLITE_INT_TO_PTR(iArg), 0, noopFunc, 0, 0, 0, #zName, {0} }
 #define DFUNCTION(zName, nArg, iArg, bNC, xFunc) \
   {nArg, SQLITE_FUNC_SLOCHNG|SQLITE_UTF8, \
    0, 0, xFunc, 0, 0, 0, #zName, {0} }
@@ -2674,23 +2735,28 @@ struct Expr {
 ** also be used as the argument to a function, in which case the a.zName
 ** field is not used.
 **
-** By default the Expr.zSpan field holds a human-readable description of
-** the expression that is used in the generation of error messages and
-** column labels.  In this case, Expr.zSpan is typically the text of a
-** column expression as it exists in a SELECT statement.  However, if
-** the bSpanIsTab flag is set, then zSpan is overloaded to mean the name
-** of the result column in the form: DATABASE.TABLE.COLUMN.  This later
-** form is used for name resolution with nested FROM clauses.
+** In order to try to keep memory usage down, the Expr.a.zEName field
+** is used for multiple purposes:
+**
+**     eEName          Usage
+**    ----------       -------------------------
+**    ENAME_NAME       (1) the AS of result set column
+**                     (2) COLUMN= of an UPDATE
+**
+**    ENAME_TAB        DB.TABLE.NAME used to resolve names
+**                     of subqueries
+**
+**    ENAME_SPAN       Text of the original result set
+**                     expression.
 */
 struct ExprList {
   int nExpr;             /* Number of expressions on the list */
   struct ExprList_item { /* For each expression in the list */
     Expr *pExpr;            /* The parse tree for this expression */
-    char *zName;            /* Token associated with this expression */
-    char *zSpan;            /* Original text of the expression */
+    char *zEName;           /* Token associated with this expression */
     u8 sortFlags;           /* Mask of KEYINFO_ORDER_* flags */
+    unsigned eEName :2;     /* Meaning of zEName */
     unsigned done :1;       /* A flag to indicate when processing is finished */
-    unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
     unsigned reusable :1;   /* Constant expression is reusable */
     unsigned bSorterRef :1; /* Defer evaluation until after sorting */
     unsigned bNulls: 1;     /* True if explicit "NULLS FIRST/LAST" */
@@ -2705,6 +2771,13 @@ struct ExprList {
 };
 
 /*
+** Allowed values for Expr.a.eEName
+*/
+#define ENAME_NAME  0       /* The AS clause of a result set */
+#define ENAME_SPAN  1       /* Complete text of the result set expression */
+#define ENAME_TAB   2       /* "DB.TABLE.NAME" for the result set */
+
+/*
 ** An instance of this structure can hold a simple list of identifiers,
 ** such as the list "a,b,c" in the following statements:
 **
@@ -3547,7 +3620,6 @@ struct Sqlite3Config {
   int (*xTestCallback)(int);        /* Invoked by sqlite3FaultSim() */
 #endif
   int bLocaltimeFault;              /* True to fail localtime() calls */
-  int bInternalFunctions;           /* Internal SQL functions are visible */
   int iOnceResetThreshold;          /* When to reset OP_Once counters */
   u32 szSorterRef;                  /* Min size in bytes to use sorter-refs */
   unsigned int iPrngSeed;           /* Alternative fixed seed for the PRNG */
@@ -3710,7 +3782,7 @@ Window *sqlite3WindowAlloc(Parse*, int, int, Expr*, int , Expr*, u8);
 void sqlite3WindowAttach(Parse*, Expr*, Window*);
 void sqlite3WindowLink(Select *pSel, Window *pWin);
 int sqlite3WindowCompare(Parse*, Window*, Window*, int);
-void sqlite3WindowCodeInit(Parse*, Window*);
+void sqlite3WindowCodeInit(Parse*, Select*);
 void sqlite3WindowCodeStep(Parse*, Select*, WhereInfo*, int, int);
 int sqlite3WindowRewrite(Parse*, Select*);
 int sqlite3ExpandSubquery(Parse*, struct SrcList_item*);
@@ -4444,7 +4516,12 @@ void sqlite3CodeRhsOfIN(Parse*, Expr*, int);
 int sqlite3CodeSubselect(Parse*, Expr*);
 void sqlite3SelectPrep(Parse*, Select*, NameContext*);
 void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p);
-int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
+int sqlite3MatchEName(
+  const struct ExprList_item*,
+  const char*,
+  const char*,
+  const char*
+);
 int sqlite3ResolveExprNames(NameContext*, Expr*);
 int sqlite3ResolveExprListNames(NameContext*, ExprList*);
 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);