Add the sqlite3ResultStrAccum() internal interface to simplify the

the implementation of functions that return strings.

FossilOrigin-Name: e548e9299d3fd6ce5b647cf0dd93ff8e917a5eda43076c6a02389c52640e2e50

5 files changed, 111 insertions, 152 deletions

diff --git a/src/analyze.c b/src/analyze.c
index e4f389ca3..d38cb1878 100644
--- a/src/analyze.c
+++ b/src/analyze.c
@@ -851,28 +851,19 @@ static void statGet(
     **
     **        I = (K+D-1)/D
     */
-    char *z;
-    int i;
-
-    char *zRet = sqlite3MallocZero( (p->nKeyCol+1)*25 );
-    if( zRet==0 ){
-      sqlite3_result_error_nomem(context);
-      return;
-    }
+    sqlite3_str sStat;   /* Text of the constructed "stat" line */
+    int i;               /* Loop counter */
 
-    sqlite3_snprintf(24, zRet, "%llu", 
+    sqlite3StrAccumInit(&sStat, 0, 0, 0, (p->nKeyCol+1)*100);
+    sqlite3_str_appendf(&sStat, "%llu", 
         p->nSkipAhead ? (u64)p->nEst : (u64)p->nRow);
-    z = zRet + sqlite3Strlen30(zRet);
     for(i=0; i<p->nKeyCol; i++){
       u64 nDistinct = p->current.anDLt[i] + 1;
       u64 iVal = (p->nRow + nDistinct - 1) / nDistinct;
-      sqlite3_snprintf(24, z, " %llu", iVal);
-      z += sqlite3Strlen30(z);
+      sqlite3_str_appendf(&sStat, " %llu", iVal);
       assert( p->current.anEq[i] );
     }
-    assert( z[0]=='\0' && z>zRet );
-
-    sqlite3_result_text(context, zRet, -1, sqlite3_free);
+    sqlite3ResultStrAccum(context, &sStat);
   }
 #ifdef SQLITE_ENABLE_STAT4
   else if( eCall==STAT_GET_ROWID ){
@@ -891,6 +882,8 @@ static void statGet(
     }
   }else{
     tRowcnt *aCnt = 0;
+    sqlite3_str sStat;
+    int i;
 
     assert( p->iGet<p->nSample );
     switch( eCall ){
@@ -902,23 +895,12 @@ static void statGet(
         break;
       }
     }
-
-    {
-      char *zRet = sqlite3MallocZero(p->nCol * 25);
-      if( zRet==0 ){
-        sqlite3_result_error_nomem(context);
-      }else{
-        int i;
-        char *z = zRet;
-        for(i=0; i<p->nCol; i++){
-          sqlite3_snprintf(24, z, "%llu ", (u64)aCnt[i]);
-          z += sqlite3Strlen30(z);
-        }
-        assert( z[0]=='\0' && z>zRet );
-        z[-1] = '\0';
-        sqlite3_result_text(context, zRet, -1, sqlite3_free);
-      }
+    sqlite3StrAccumInit(&sStat, 0, 0, 0, p->nCol*100);
+    for(i=0; i<p->nCol; i++){
+      sqlite3_str_appendf(&sStat, "%llu ", (u64)aCnt[i]);
     }
+    if( sStat.nChar ) sStat.nChar--;
+    sqlite3ResultStrAccum(context, &sStat);
   }
 #endif /* SQLITE_ENABLE_STAT4 */
 #ifndef SQLITE_DEBUG
diff --git a/src/date.c b/src/date.c
index f88f544e3..fb83ad187 100644
--- a/src/date.c
+++ b/src/date.c
@@ -1009,131 +1009,100 @@ static void strftimeFunc(
   sqlite3_value **argv
 ){
   DateTime x;
-  u64 n;
   size_t i,j;
-  char *z;
   sqlite3 *db;
   const char *zFmt;
-  char zBuf[100];
+  sqlite3_str sRes;
+
+
   if( argc==0 ) return;
   zFmt = (const char*)sqlite3_value_text(argv[0]);
   if( zFmt==0 || isDate(context, argc-1, argv+1, &x) ) return;
   db = sqlite3_context_db_handle(context);
-  for(i=0, n=1; zFmt[i]; i++, n++){
-    if( zFmt[i]=='%' ){
-      switch( zFmt[i+1] ){
-        case 'd':
-        case 'H':
-        case 'm':
-        case 'M':
-        case 'S':
-        case 'W':
-          n++;
-          /* fall thru */
-        case 'w':
-        case '%':
-          break;
-        case 'f':
-          n += 8;
-          break;
-        case 'j':
-          n += 3;
-          break;
-        case 'Y':
-          n += 8;
-          break;
-        case 's':
-        case 'J':
-          n += 50;
-          break;
-        default:
-          return;  /* ERROR.  return a NULL */
-      }
-      i++;
-    }
-  }
-  testcase( n==sizeof(zBuf)-1 );
-  testcase( n==sizeof(zBuf) );
-  testcase( n==(u64)db->aLimit[SQLITE_LIMIT_LENGTH]+1 );
-  testcase( n==(u64)db->aLimit[SQLITE_LIMIT_LENGTH] );
-  if( n<sizeof(zBuf) ){
-    z = zBuf;
-  }else if( n>(u64)db->aLimit[SQLITE_LIMIT_LENGTH] ){
-    sqlite3_result_error_toobig(context);
-    return;
-  }else{
-    z = sqlite3DbMallocRawNN(db, (int)n);
-    if( z==0 ){
-      sqlite3_result_error_nomem(context);
-      return;
-    }
-  }
+  sqlite3StrAccumInit(&sRes, 0, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);
+
   computeJD(&x);
   computeYMD_HMS(&x);
   for(i=j=0; zFmt[i]; i++){
-    if( zFmt[i]!='%' ){
-      z[j++] = zFmt[i];
-    }else{
-      i++;
-      switch( zFmt[i] ){
-        case 'd':  sqlite3_snprintf(3, &z[j],"%02d",x.D); j+=2; break;
-        case 'f': {
-          double s = x.s;
-          if( s>59.999 ) s = 59.999;
-          sqlite3_snprintf(7, &z[j],"%06.3f", s);
-          j += sqlite3Strlen30(&z[j]);
-          break;
-        }
-        case 'H':  sqlite3_snprintf(3, &z[j],"%02d",x.h); j+=2; break;
-        case 'W': /* Fall thru */
-        case 'j': {
-          int nDay;             /* Number of days since 1st day of year */
-          DateTime y = x;
-          y.validJD = 0;
-          y.M = 1;
-          y.D = 1;
-          computeJD(&y);
-          nDay = (int)((x.iJD-y.iJD+43200000)/86400000);
-          if( zFmt[i]=='W' ){
-            int wd;   /* 0=Monday, 1=Tuesday, ... 6=Sunday */
-            wd = (int)(((x.iJD+43200000)/86400000)%7);
-            sqlite3_snprintf(3, &z[j],"%02d",(nDay+7-wd)/7);
-            j += 2;
-          }else{
-            sqlite3_snprintf(4, &z[j],"%03d",nDay+1);
-            j += 3;
-          }
-          break;
-        }
-        case 'J': {
-          sqlite3_snprintf(20, &z[j],"%.16g",x.iJD/86400000.0);
-          j+=sqlite3Strlen30(&z[j]);
-          break;
-        }
-        case 'm':  sqlite3_snprintf(3, &z[j],"%02d",x.M); j+=2; break;
-        case 'M':  sqlite3_snprintf(3, &z[j],"%02d",x.m); j+=2; break;
-        case 's': {
-          i64 iS = (i64)(x.iJD/1000 - 21086676*(i64)10000);
-          sqlite3Int64ToText(iS, &z[j]);
-          j += sqlite3Strlen30(&z[j]);
-          break;
-        }
-        case 'S':  sqlite3_snprintf(3,&z[j],"%02d",(int)x.s); j+=2; break;
-        case 'w': {
-          z[j++] = (char)(((x.iJD+129600000)/86400000) % 7) + '0';
-          break;
-        }
-        case 'Y': {
-          sqlite3_snprintf(5,&z[j],"%04d",x.Y); j+=sqlite3Strlen30(&z[j]);
-          break;
+    if( zFmt[i]!='%' ) continue;
+    if( j<i ) sqlite3_str_append(&sRes, zFmt+j, i-j);
+    i++;
+    j = i + 1;
+    switch( zFmt[i] ){
+      case 'd': {
+        sqlite3_str_appendf(&sRes, "%02d", x.D);
+        break;
+      }
+      case 'f': {
+        double s = x.s;
+        if( s>59.999 ) s = 59.999;
+        sqlite3_str_appendf(&sRes, "%06.3f", s);
+        break;
+      }
+      case 'H': {
+        sqlite3_str_appendf(&sRes, "%02d", x.h);
+        break;
+      }
+      case 'W': /* Fall thru */
+      case 'j': {
+        int nDay;             /* Number of days since 1st day of year */
+        DateTime y = x;
+        y.validJD = 0;
+        y.M = 1;
+        y.D = 1;
+        computeJD(&y);
+        nDay = (int)((x.iJD-y.iJD+43200000)/86400000);
+        if( zFmt[i]=='W' ){
+          int wd;   /* 0=Monday, 1=Tuesday, ... 6=Sunday */
+          wd = (int)(((x.iJD+43200000)/86400000)%7);
+          sqlite3_str_appendf(&sRes,"%02d",(nDay+7-wd)/7);
+        }else{
+          sqlite3_str_appendf(&sRes,"%03d",nDay+1);
         }
-        default:   z[j++] = '%'; break;
+        break;
+      }
+      case 'J': {
+        sqlite3_str_appendf(&sRes,"%.16g",x.iJD/86400000.0);
+        break;
+      }
+      case 'm': {
+        sqlite3_str_appendf(&sRes,"%02d",x.M);
+        break;
+      }
+      case 'M': {
+        sqlite3_str_appendf(&sRes,"%02d",x.m);
+        break;
+      }
+      case 's': {
+        i64 iS = (i64)(x.iJD/1000 - 21086676*(i64)10000);
+        sqlite3_str_appendf(&sRes,"%lld",iS);
+        break;
+      }
+      case 'S': {
+        sqlite3_str_appendf(&sRes,"%02d",(int)x.s);
+        break;
+      }
+      case 'w': {
+        sqlite3_str_appendchar(&sRes, 1,
+                       (char)(((x.iJD+129600000)/86400000) % 7) + '0');
+        break;
+      }
+      case 'Y': {
+        sqlite3_str_appendf(&sRes,"%04d",x.Y);
+        break;
+      }
+      case '%': {
+        sqlite3_str_appendchar(&sRes, 1, '%');
+        break;
+      }
+      default: {
+        sqlite3_str_reset(&sRes);
+        return;
       }
     }
   }
-  z[j] = 0;
-  sqlite3_result_text(context, z, -1,
-                      z==zBuf ? SQLITE_TRANSIENT : SQLITE_DYNAMIC);
+  if( j<i ) sqlite3_str_append(&sRes, zFmt+j, i-j);
+  sqlite3ResultStrAccum(context, &sRes);
 }
 
 /*
diff --git a/src/func.c b/src/func.c
index 900ea94c6..754ffc50e 100644
--- a/src/func.c
+++ b/src/func.c
@@ -1853,16 +1853,7 @@ static void groupConcatFinalize(sqlite3_context *context){
   GroupConcatCtx *pGCC
     = (GroupConcatCtx*)sqlite3_aggregate_context(context, 0);
   if( pGCC ){
-    StrAccum *pAccum = &pGCC->str;
-    if( pAccum->accError==SQLITE_TOOBIG ){
-      sqlite3_result_error_toobig(context);
-    }else if( pAccum->accError==SQLITE_NOMEM ){
-      sqlite3_result_error_nomem(context);
-    }else{
-      int n = pAccum->nChar;
-      sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), n, 
-                          sqlite3_free);
-    }
+    sqlite3ResultStrAccum(context, &pGCC->str);
 #ifndef SQLITE_OMIT_WINDOWFUNC
     sqlite3_free(pGCC->pnSepLengths);
 #endif
diff --git a/src/printf.c b/src/printf.c
index eb06e1a23..e63518450 100644
--- a/src/printf.c
+++ b/src/printf.c
@@ -1045,6 +1045,22 @@ char *sqlite3StrAccumFinish(StrAccum *p){
 }
 
 /*
+** Use the content of the StrAccum passed as the second argument
+** as the result of an SQL function.
+*/
+void sqlite3ResultStrAccum(sqlite3_context *pCtx, StrAccum *p){
+  if( p->accError ){
+    sqlite3_result_error_code(pCtx, p->accError);
+    sqlite3_str_reset(p);
+  }else if( isMalloced(p) ){
+    sqlite3_result_text(pCtx, p->zText, p->nChar, SQLITE_DYNAMIC);
+  }else{
+    sqlite3_result_text(pCtx, "", 0, SQLITE_STATIC);
+    sqlite3_str_reset(p);
+  }
+}
+
+/*
 ** This singleton is an sqlite3_str object that is returned if
 ** sqlite3_malloc() fails to provide space for a real one.  This
 ** sqlite3_str object accepts no new text and always returns
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index c1e0638dc..a7f830263 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -4941,6 +4941,7 @@ int sqlite3OpenTempDatabase(Parse *);
 void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
 char *sqlite3StrAccumFinish(StrAccum*);
 void sqlite3StrAccumSetError(StrAccum*, u8);
+void sqlite3ResultStrAccum(sqlite3_context*,StrAccum*);
 void sqlite3SelectDestInit(SelectDest*,int,int);
 Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);