From: drh <drh@noemail.net>
Date: Tue, 11 Jul 2017 02:05:21 +0000 (+0000)
Subject: Add the "phase" output column on the COMPLETION table-valued function, for
X-Git-Tag: version-3.20.0~81
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f3c0009d8b9208123e41da64b2c757c2f307c95f;p=thirdparty%2Fsqlite.git

Add the "phase" output column on the COMPLETION table-valued function, for
debugging.  Improved comments on the implementation.

FossilOrigin-Name: 0e2135552757cc6566ac959475d3b87254b6d462425ee6c457c743001f3370e2
---

diff --git a/ext/misc/completion.c b/ext/misc/completion.c
index ae11ef4220..a3189ad154 100644
--- a/ext/misc/completion.c
+++ b/ext/misc/completion.c
@@ -13,6 +13,25 @@
 ** This file implements an eponymous virtual table that returns suggested
 ** completions for a partial SQL input.
 **
+** Suggested usage:
+**
+**     SELECT DISTINCT candidate COLLATE nocase
+**       FROM completion($prefix,$wholeline)
+**      ORDER BY 1;
+**
+** The two query parameters are optional.  $prefix is the text of the
+** current word being typed and that is to be completed.  $wholeline is
+** the complete input line, used for context.
+**
+** The raw completion() table might return the same candidate multiple
+** times, for example if the same column name is used to two or more
+** tables.  And the candidates are returned in an arbitrary order.  Hence,
+** the DISTINCT and ORDER BY are recommended.
+**
+** This virtual table operates at the speed of human typing, and so there
+** is no attempt to make it fast.  Even a slow implementation will be much
+** faster than any human can type.
+**
 */
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_COMPLETIONVTAB)
 #if !defined(SQLITEINT_H)
@@ -94,12 +113,14 @@ static int completionConnect(
 #define COMPLETION_COLUMN_CANDIDATE 0  /* Suggested completion of the input */
 #define COMPLETION_COLUMN_PREFIX    1  /* Prefix of the word to be completed */
 #define COMPLETION_COLUMN_WHOLELINE 2  /* Entire line seen so far */
+#define COMPLETION_COLUMN_PHASE     3  /* ePhase - used for debugging only */
 
   rc = sqlite3_declare_vtab(db,
       "CREATE TABLE x("
       "  candidate TEXT,"
       "  prefix TEXT HIDDEN,"
-      "  wholeline TEXT HIDDEN"
+      "  wholeline TEXT HIDDEN,"
+      "  phase INT HIDDEN"        /* Used for debugging only */
       ")");
   if( rc==SQLITE_OK ){
     pNew = sqlite3_malloc( sizeof(*pNew) );
@@ -177,11 +198,22 @@ static const char *completionKwrds[] = {
 
 /*
 ** Advance a completion_cursor to its next row of output.
+**
+** The ->ePhase, ->j, and ->pStmt fields of the completion_cursor object
+** record the current state of the scan.  This routine sets ->zCurrentRow
+** to the current row of output and then returns.  If no more rows remain,
+** then ->ePhase is set to COMPLETION_EOF which will signal the virtual
+** table that has reached the end of its scan.
+**
+** The current implementation just lists potential identifiers and
+** keywords and filters them by zPrefix.  Future enhancements should
+** take zLine into account to try to restrict the set of identifiers and
+** keywords based on what would be legal at the current point of input.
 */
 static int completionNext(sqlite3_vtab_cursor *cur){
   completion_cursor *pCur = (completion_cursor*)cur;
-  int eNextPhase = 0;/* Next phase to try if current phase reaches end */
-  int iCol = -1;     /* If >=0 then step pCur->pStmt and use the i-th column */
+  int eNextPhase = 0;  /* Next phase to try if current phase reaches end */
+  int iCol = -1;       /* If >=0, step pCur->pStmt and use the i-th column */
   pCur->iRowid++;
   while( pCur->ePhase!=COMPLETION_EOF ){
     switch( pCur->ePhase ){
@@ -303,6 +335,10 @@ static int completionColumn(
       sqlite3_result_text(ctx, pCur->zLine, -1, SQLITE_TRANSIENT);
       break;
     }
+    case COMPLETION_COLUMN_PHASE: {
+      sqlite3_result_int(ctx, pCur->ePhase);
+      break;
+    }
   }
   return SQLITE_OK;
 }
diff --git a/manifest b/manifest
index 2900651ce0..c66c5490f5 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C The\sCOMPLETION\svirtual\stable\snow\slooks\sat\sthe\snames\sof\sdatabases,\stables,\nand\scolumns\sin\saddition\sto\sSQL\skeywords.
-D 2017-07-11T01:38:45.049
+C Add\sthe\s"phase"\soutput\scolumn\son\sthe\sCOMPLETION\stable-valued\sfunction,\sfor\ndebugging.\s\sImproved\scomments\son\sthe\simplementation.
+D 2017-07-11T02:05:21.668
 F Makefile.in 081e48dfe7f995d57ce1a88ddf4d2917b4349158648a6cd45b42beae30de3a12
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 20850e3e8d4d4791e0531955852d768eb06f24138214870d543abb1a47346fba
@@ -256,7 +256,7 @@ F ext/misc/amatch.c 6db4607cb17c54b853a2d7c7c36046d004853f65b9b733e6f019d543d5df
 F ext/misc/anycollseq.c 5ffdfde9829eeac52219136ad6aa7cd9a4edb3b15f4f2532de52f4a22525eddb
 F ext/misc/carray.c 40c27641010a4dc67e3690bdb7c9d36ca58b3c2d
 F ext/misc/closure.c 0d2a038df8fbae7f19de42e7c7d71f2e4dc88704
-F ext/misc/completion.c 813c7faecc8fe3dd5c5503b87d4bb44ed6b841ff3398d19fbccec251da0af25f
+F ext/misc/completion.c 637c016977809c2c3174472e7a416c9dbefc89dadb0efbd33f1516114b43900e
 F ext/misc/compress.c 122faa92d25033d6c3f07c39231de074ab3d2e83
 F ext/misc/csv.c d91c0388445b08f6e373dd0e8fc024d4551b1fcaf64e876a1c3f4fac8a63adc2
 F ext/misc/dbdump.c 3509fa6b8932d04e932d6b6b827b6a82ca362781b8e8f3c77336f416793e215e
@@ -1629,7 +1629,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P caefbc723b5f67afc5ef10b92b20400cbb76cb03e7e75e18d2726cc552083e09
-R 1115796824efacad1a0f50faf8b6a73d
+P 1cc97711fa86a3938f0930200476d1b0991e4b893a8be3a19015423a3de56bef
+R 5f96666448f8bc2a00b6b737201e92f6
 U drh
-Z e368c5a978df04c5e378d21fe41e060f
+Z 37fc96f83608b2443df93123a3a88569
diff --git a/manifest.uuid b/manifest.uuid
index d37dfde610..48e5077089 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-1cc97711fa86a3938f0930200476d1b0991e4b893a8be3a19015423a3de56bef
\ No newline at end of file
+0e2135552757cc6566ac959475d3b87254b6d462425ee6c457c743001f3370e2
\ No newline at end of file