Experimental sqlite3_stmt_retryable() interface.

FossilOrigin-Name: ebada0723ac91f288fe89baf4a7eb6383f71d6588afaf17467f45a56677de22d

diff --git a/manifest b/manifest
index 42cba1232ce9b2ff19cb1c0e9fe87b4f49e56eba..c2f0637f6a0778fa629a1e9f8ef11143a9963147 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Disable\sFTS3\smatchinfo()\stests\sthat\sassume\sa\slittleEndian\splatform\swhen\nrunning\son\sbigEndian.
-D 2017-09-13T12:55:59.555
+C Experimental\ssqlite3_stmt_retryable()\sinterface.
+D 2017-09-13T18:38:31.171
 F Makefile.in c644bbe8ebe4aae82ad6783eae6b6beea4c727b99ff97568b847ced5e2ac7afb
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 6a7a74bf60ad395098c0bd175ab054cd65ef85d7f034198d52bcc4d9e5fb4c6b
@@ -422,7 +422,7 @@ F src/in-operator.md 10cd8f4bcd225a32518407c2fb2484089112fd71
 F src/insert.c d2d1bf12d2b5382450620d7cede84c7ffe57e6a89fa9a908f1aba68df2731cd9
 F src/legacy.c 134ab3e3fae00a0f67a5187981d6935b24b337bcf0f4b3e5c9fa5763da95bf4e
 F src/loadext.c 20865b183bb8a3723d59cf1efffc3c50217eb452c1021d077b908c94da26b0b2
-F src/main.c 34a58563358fe40979186124d1a3614b9a00c833124d7ebfa8e5d604ed1d2521
+F src/main.c 39f1375c02ea2d201bd09efcc09dcbb7ebce241280fa17bb7aa4ef7cc718061c
 F src/malloc.c a02c9e69bc76bee0f639416b947a946412890b606301454727feadcb313536d6
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c c12a42539b1ba105e3707d0e628ad70e611040d8f5e38cf942cee30c867083de
@@ -458,12 +458,12 @@ F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 4324a94573b1e29286f8121e4881db59eaedc014afeb274c8d3e07ed282e0e20
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
 F src/select.c c9b3d8444bbf6f167d84f41ca6f3672e2521cb163a8c706b19058dc82fffe9b8
-F src/shell.c c1206a23d9239f8f51751d3be9b8c3b02fa4103546bea1add7f864d84a8276ab
-F src/shell.c.in bb9720a8c5c98d3984b16ab7540e7142bcae959666ecf248bfc523a1d44220ee
-F src/sqlite.h.in ab4f8a29d1580dfaeb6891fa1b83cff8229ba0daa56994707ceaca71495d9ab7
+F src/shell.c dc398976107b68dadccce23d27d0fd16f8409b1d782612969866aab015799582
+F src/shell.c.in 30d6799f86445a8b989bed45c7d5f33c8192d838605e0abe99e0398892779974
+F src/sqlite.h.in eea8fde8bf4f3ab8b82ab3dce54f86b113f75cf48fd43ce92efd2f0cd7cc6e61
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h a1fd3aa82f967da436164e0728a7d6841651fd0c6e27b9044e0eb9f6c8462e47
-F src/sqliteInt.h 2272cd09b7f137bb2423af589d636b5b741037db9b329d359c1ef6556fac5a4c
+F src/sqliteInt.h 0568e9b1aed70ea7db3630820e9e35ed6a87ea6ef3ae20693467d8eb255639e3
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 9737ed017279a9e0c5da748701c3c7bf1e8ae0dae459aad20dd64fcff97a7e35
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -527,9 +527,9 @@ F src/util.c ece10cb34b4a62cbb3aab8d711b67e93a2765e0b81d0f72458cb801a3ac60703
 F src/vacuum.c 90839322fd5f00df9617eb21b68beda9b6e2a2937576b0d65985e4aeb1c53739
 F src/vdbe.c 0a0ef7f0759ee4c3ed5ff0c6e9641216d4b31ebb0fea9a7b5a9c4a86ce875ff3
 F src/vdbe.h d50cadf12bcf9fb99117ef392ce1ea283aa429270481426b6e8b0280c101fd97
-F src/vdbeInt.h 1fe00770144c12c4913128f35262d11527ef3284561baaab59b947a41c08d0d9
-F src/vdbeapi.c 9c670ca0dcc1cd86373aa353b747b26fe531ca5cd4331690c611d1f03842e2a1
-F src/vdbeaux.c 41d90002d774e234f95d1298fc70d25e3420e8d9ebd65aa270a8b771c5525790
+F src/vdbeInt.h 207b6ac7842768601bd5563a0c5dfad9b7dc10be5577d71d8fb53258bfd371f2
+F src/vdbeapi.c e706b81a65f879e7b9640248a386ef5f90e29d61169680e64803d2eafe407763
+F src/vdbeaux.c 0b2b1942102b33060bd960cc5c1d4997394ffa7f7189148dab4af5187fa09191
 F src/vdbeblob.c db3cf91060f6f4b2f1358a4200e844697990752177784c7c95da00b7ac9f1c7b
 F src/vdbemem.c 2f9d672af5260f0145787e1dc2c6985414987cc0dc575133a0dc17dda767d868
 F src/vdbesort.c 731a09e5cb9e96b70c394c1b7cf3860fbe84acca7682e178615eb941a3a0ef2f
@@ -1653,7 +1653,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 8525c30c1d6676e51b9d9c642450aae3722c129edafdbc39b8435fcfe09b1817
-R 6ec072e8cc5f89299e9fb58896934d7c
+P 87ccdf9cbb9284553330683d4971be4f523ce922089aee6dffccfc18b3004263
+R e43ecae42b6f451608f028a9fca6964c
+T *branch * sqlite3_stmt_retryable
+T *sym-sqlite3_stmt_retryable *
+T -sym-trunk *
 U drh
-Z 5fb925822a75ef5ce57cd890a3d631bf
+Z 5c6219255517ab512c38a3a9f7c2d38b

diff --git a/manifest.uuid b/manifest.uuid
index 5e4e028228efacf16a59562325b46500ec322bc1..e21dc801413aacedc093e95b51d781ca14b60a05 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-87ccdf9cbb9284553330683d4971be4f523ce922089aee6dffccfc18b3004263
\ No newline at end of file
+ebada0723ac91f288fe89baf4a7eb6383f71d6588afaf17467f45a56677de22d
\ No newline at end of file

diff --git a/src/main.c b/src/main.c
index 3942ed9465923e3e49c9c389e29afd1150f82155..aaf49acdd125f4607615b42a517b862a1895bc64 100644 (file)
--- a/src/main.c
+++ b/src/main.c
@@ -1506,9 +1506,13 @@ static int sqliteDefaultBusyCallback(
 */
 int sqlite3InvokeBusyHandler(BusyHandler *p){
   int rc;
-  if( NEVER(p==0) || p->xFunc==0 || p->nBusy<0 ) return 0;
+  if( p->xFunc==0 || p->nBusy<0 ){
+    p->nTimeout++;
+    return 0;
+  }
   rc = p->xFunc(p->pArg, p->nBusy);
   if( rc==0 ){
+    p->nTimeout++;
     p->nBusy = -1;
   }else{
     p->nBusy++;

diff --git a/src/shell.c b/src/shell.c
index 6a19e3610a1b9921a628efe59b7238df4ab82572..1825eec8727ffca3f9180a8de40ebfb6c96573ff 100644 (file)
--- a/src/shell.c
+++ b/src/shell.c
@@ -3617,7 +3617,7 @@ static int shell_exec(
 ){
   sqlite3_stmt *pStmt = NULL;     /* Statement to execute. */
   int rc = SQLITE_OK;             /* Return Code */
-  int rc2;
+  int rc2, rc3;
   const char *zLeftover;          /* Tail of unprocessed SQL */
 
   if( pzErrMsg ){
@@ -3718,13 +3718,23 @@ static int shell_exec(
       /* Finalize the statement just executed. If this fails, save a
       ** copy of the error message. Otherwise, set zSql to point to the
       ** next statement to execute. */
+      rc3 = sqlite3_stmt_retryable(pStmt);
       rc2 = sqlite3_finalize(pStmt);
       if( rc!=SQLITE_NOMEM ) rc = rc2;
       if( rc==SQLITE_OK ){
         zSql = zLeftover;
         while( IsSpace(zSql[0]) ) zSql++;
-      }else if( pzErrMsg ){
-        *pzErrMsg = save_err_msg(db);
+      }else{
+        if( rc==SQLITE_BUSY ){
+          if( rc3 ){
+            raw_printf(pArg->out, "Busy: might succeed on retry\n");
+          }else{
+            raw_printf(pArg->out, "Busy: cannot succeed - rollback required\n");
+          }
+        }
+        if( pzErrMsg ){
+          *pzErrMsg = save_err_msg(db);
+        }
       }
 
       /* clear saved stmt handle */

diff --git a/src/shell.c.in b/src/shell.c.in
index 82680d484c724e767f90a305812c99029a5cb320..62c9a7529727141e9c6cebc58816e25d04a86982 100644 (file)
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -2257,7 +2257,7 @@ static int shell_exec(
 ){
   sqlite3_stmt *pStmt = NULL;     /* Statement to execute. */
   int rc = SQLITE_OK;             /* Return Code */
-  int rc2;
+  int rc2, rc3;
   const char *zLeftover;          /* Tail of unprocessed SQL */
 
   if( pzErrMsg ){
@@ -2358,13 +2358,23 @@ static int shell_exec(
       /* Finalize the statement just executed. If this fails, save a
       ** copy of the error message. Otherwise, set zSql to point to the
       ** next statement to execute. */
+      rc3 = sqlite3_stmt_retryable(pStmt);
       rc2 = sqlite3_finalize(pStmt);
       if( rc!=SQLITE_NOMEM ) rc = rc2;
       if( rc==SQLITE_OK ){
         zSql = zLeftover;
         while( IsSpace(zSql[0]) ) zSql++;
-      }else if( pzErrMsg ){
-        *pzErrMsg = save_err_msg(db);
+      }else{
+        if( rc==SQLITE_BUSY ){
+          if( rc3 ){
+            raw_printf(pArg->out, "Busy: might succeed on retry\n");
+          }else{
+            raw_printf(pArg->out, "Busy: cannot succeed - rollback required\n");
+          }
+        }
+        if( pzErrMsg ){
+          *pzErrMsg = save_err_msg(db);
+        }
       }
 
       /* clear saved stmt handle */

diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 9ff366304f201a3198c817924a6a10f4d695ee93..99f49d9e3a598b9a8f4bf5713d4223ebb28f75ce 100644 (file)
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -3764,6 +3764,18 @@ char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
 */
 int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
 
+/*
+** CAPI3REF: Determine If An SQL Statement Can Be Retried After SQLITE_BUSY
+** METHOD: sqlite3_stmt
+**
+** ^The sqlite3_stmt_retryable(X) interface returns true (non-zero) if
+** the previous run of [prepared statement] X failed with an
+** [SQLITE_BUSY] error but might succeed if run again.  If X has not been
+** previously run or if the previous run of X did not return SQLITE_BUSY,
+** then the result of this function is a meaningless boolean.
+*/
+int sqlite3_stmt_retryable(sqlite3_stmt *pStmt);
+
 /*
 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
 ** METHOD: sqlite3_stmt

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 58d64ba2f21147e52ffcdb7852b8696da1d1b10e..d80334f26e8487e80563b1a7d258fc2ddde44640 100644 (file)
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -949,6 +949,7 @@ struct BusyHandler {
   int (*xFunc)(void *,int);  /* The busy callback */
   void *pArg;                /* First arg to busy callback */
   int nBusy;                 /* Incremented with each busy call */
+  u32 nTimeout;              /* Number of timeouts */
 };
 
 /*

diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index cb783653c0beb01f31642c2c7739d572294efe41..4000ecc0e72b4b56c28fd34b9d19ecceb7d020e6 100644 (file)
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -393,6 +393,7 @@ struct Vdbe {
   bft usesStmtJournal:1;  /* True if uses a statement journal */
   bft readOnly:1;         /* True for statements that do not write */
   bft bIsReader:1;        /* True for statements that read */
+  bft retryable:1;        /* True if the statement might succeed next time */
   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
   u32 aCounter[7];        /* Counters used by sqlite3_stmt_status() */

diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index b9df40b8fd35357c7c1f7b105170706ccd7fd843..96f1ef175b8ce79c60bb3d0969cb1b6f535bd962 100644 (file)
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -1613,6 +1613,14 @@ int sqlite3_stmt_readonly(sqlite3_stmt *pStmt){
   return pStmt ? ((Vdbe*)pStmt)->readOnly : 1;
 }
 
+/*
+** Return true if the prepared statement failed with SQLITE_BUSY on its
+** previous run but might succeed if tried again.
+*/
+int sqlite3_stmt_retryable(sqlite3_stmt *pStmt){
+  return pStmt ? ((Vdbe*)pStmt)->retryable : 0;
+}
+
 /*
 ** Return true if the prepared statement is in need of being reset.
 */

diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index e5465d16e76889970406f44557496a609272fd32..34c78e35c76a2d88a2ee4f3d78e1c4fd3037409c 100644 (file)
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -2702,7 +2702,9 @@ int sqlite3VdbeHalt(Vdbe *p){
           ** or hit an 'OR FAIL' constraint and there are no deferred foreign
           ** key constraints to hold up the transaction. This means a commit 
           ** is required. */
+          db->busyHandler.nTimeout = 0;
           rc = vdbeCommit(db, p);
+          p->retryable = db->busyHandler.nTimeout>0;
         }
         if( rc==SQLITE_BUSY && p->readOnly ){
           sqlite3VdbeLeave(p);