[tarantool-patches] [PATCH v5 2/2] sql: remove busy handler

[Stanislav Zudin <szudin@tarantool.org>]

SQLite's busyHandler functionality and functions sqlite3_sleep(),
sqlite3OsSleep() were not used and were removed.
Also removed unreachable error handling.

Closes #3733
---
 src/box/sql/main.c      | 76 -----------------------------------------
 src/box/sql/os.c        |  6 ----
 src/box/sql/os.h        |  1 -
 src/box/sql/os_unix.c   | 18 ----------
 src/box/sql/pragma.c    | 22 ++----------
 src/box/sql/pragma.h    |  8 -----
 src/box/sql/sqliteInt.h | 23 -------------
 src/box/sql/vdbe.c      |  1 -
 8 files changed, 3 insertions(+), 152 deletions(-)

diff --git a/src/box/sql/main.c b/src/box/sql/main.c
index 8574d6464..5555cb48e 100644
--- a/src/box/sql/main.c
+++ b/src/box/sql/main.c
@@ -640,43 +640,6 @@ sqlite3ErrStr(int rc)
 	return zErr;
 }
 
-/*
- * This routine implements a busy callback that sleeps and tries
- * again until a timeout value is reached.  The timeout value is
- * an integer number of milliseconds passed in as the first
- * argument.
- */
-static int
-sqliteDefaultBusyCallback(void *ptr,	/* Database connection */
-			  int count)	/* Number of times table has been busy */
-{
-	sqlite3 *db = (sqlite3 *) ptr;
-	int timeout = ((sqlite3 *) ptr)->busyTimeout;
-	if ((count + 1) * 1000 > timeout) {
-		return 0;
-	}
-	sqlite3OsSleep(db->pVfs, 1000000);
-	return 1;
-}
-
-/*
- * This routine sets the busy callback for an Sqlite database to the
- * given callback function with the given argument.
- */
-int
-sqlite3_busy_handler(sqlite3 * db, int (*xBusy) (void *, int), void *pArg)
-{
-#ifdef SQLITE_ENABLE_API_ARMOR
-	if (!sqlite3SafetyCheckOk(db))
-		return SQLITE_MISUSE_BKPT;
-#endif
-	db->busyHandler.xFunc = xBusy;
-	db->busyHandler.pArg = pArg;
-	db->busyHandler.nBusy = 0;
-	db->busyTimeout = 0;
-	return SQLITE_OK;
-}
-
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
 /*
  * This routine sets the progress callback for an Sqlite database to the
@@ -705,26 +668,6 @@ sqlite3_progress_handler(sqlite3 * db,
 }
 #endif
 
-/*
- * This routine installs a default busy handler that waits for the
- * specified number of milliseconds before returning 0.
- */
-int
-sqlite3_busy_timeout(sqlite3 * db, int ms)
-{
-#ifdef SQLITE_ENABLE_API_ARMOR
-	if (!sqlite3SafetyCheckOk(db))
-		return SQLITE_MISUSE_BKPT;
-#endif
-	if (ms > 0) {
-		sqlite3_busy_handler(db, sqliteDefaultBusyCallback, (void *)db);
-		db->busyTimeout = ms;
-	} else {
-		sqlite3_busy_handler(db, 0, 0);
-	}
-	return SQLITE_OK;
-}
-
 /*
  * Cause any pending operation to stop at its earliest opportunity.
  */
@@ -1676,25 +1619,6 @@ sqlite3IoerrnomemError(int lineno)
 }
 #endif
 
-/*
- * Sleep for a little while.  Return the amount of time slept.
- */
-int
-sqlite3_sleep(int ms)
-{
-	sqlite3_vfs *pVfs;
-	int rc;
-	pVfs = sqlite3_vfs_find(0);
-	if (pVfs == 0)
-		return 0;
-
-	/* This function works in milliseconds, but the underlying OsSleep()
-	 * API uses microseconds. Hence the 1000's.
-	 */
-	rc = (sqlite3OsSleep(pVfs, 1000 * ms) / 1000);
-	return rc;
-}
-
 /*
  * Enable or disable the extended result codes.
  */
diff --git a/src/box/sql/os.c b/src/box/sql/os.c
index 1fa6b332a..3840258dc 100644
--- a/src/box/sql/os.c
+++ b/src/box/sql/os.c
@@ -128,12 +128,6 @@ sqlite3OsRandomness(sqlite3_vfs * pVfs, int nByte, char *zBufOut)
 	return pVfs->xRandomness(pVfs, nByte, zBufOut);
 }
 
-int
-sqlite3OsSleep(sqlite3_vfs * pVfs, int nMicro)
-{
-	return pVfs->xSleep(pVfs, nMicro);
-}
-
 int
 sqlite3OsGetLastError(sqlite3_vfs * pVfs)
 {
diff --git a/src/box/sql/os.h b/src/box/sql/os.h
index 947658300..c844fe7fa 100644
--- a/src/box/sql/os.h
+++ b/src/box/sql/os.h
@@ -146,7 +146,6 @@ int sqlite3OsUnfetch(sqlite3_file *, i64, void *);
  */
 int sqlite3OsOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int *);
 int sqlite3OsRandomness(sqlite3_vfs *, int, char *);
-int sqlite3OsSleep(sqlite3_vfs *, int);
 int sqlite3OsGetLastError(sqlite3_vfs *);
 int sqlite3OsCurrentTimeInt64(sqlite3_vfs *, sqlite3_int64 *);
 
diff --git a/src/box/sql/os_unix.c b/src/box/sql/os_unix.c
index b8816e0f9..2cbcd6db1 100644
--- a/src/box/sql/os_unix.c
+++ b/src/box/sql/os_unix.c
@@ -1988,23 +1988,6 @@ unixRandomness(sqlite3_vfs * NotUsed, int nBuf, char *zBuf)
 	return nBuf;
 }
 
-/*
- * Sleep for a little while.  Return the amount of time slept.
- * The argument is the number of microseconds we want to sleep.
- * The return value is the number of microseconds of sleep actually
- * requested from the underlying operating system, a number which
- * might be greater than or equal to the argument, but not less
- * than the argument.
- */
-static int
-unixSleep(sqlite3_vfs * NotUsed, int microseconds)
-{
-	int seconds = (microseconds + 999999) / 1000000;
-	sleep(seconds);
-	UNUSED_PARAMETER(NotUsed);
-	return seconds * 1000000;
-}
-
 /* Fake system time in seconds since 1970. */
 int sqlite3_current_time = 0;
 
@@ -2078,7 +2061,6 @@ unixGetLastError(sqlite3_vfs * NotUsed, int NotUsed2, char *NotUsed3)
     unixOpen,             /* xOpen */                       \
     unixDelete,           /* xDelete */                     \
     unixRandomness,       /* xRandomness */                 \
-    unixSleep,            /* xSleep */                      \
     NULL,                 /* xCurrentTime */                \
     unixGetLastError,     /* xGetLastError */               \
     unixCurrentTimeInt64, /* xCurrentTimeInt64 */           \
diff --git a/src/box/sql/pragma.c b/src/box/sql/pragma.c
index 7285455c9..1b456e0b5 100644
--- a/src/box/sql/pragma.c
+++ b/src/box/sql/pragma.c
@@ -464,7 +464,6 @@ sqlite3Pragma(Parse * pParse, Token * pId,	/* First part of [schema.]id field */
 		zRight = sqlite3NameFromToken(db, pValue);
 	}
 	zTable = sqlite3NameFromToken(db, pValue2);
-	db->busyHandler.nBusy = 0;
 
 	/* Locate the pragma in the lookup table */
 	pPragma = pragmaLocate(zLeft);
@@ -644,24 +643,9 @@ sqlite3Pragma(Parse * pParse, Token * pId,	/* First part of [schema.]id field */
 		break;
 	}
 
-	/* *   PRAGMA busy_timeout *   PRAGMA busy_timeout = N *
-	 *
-	 * Call sqlite3_busy_timeout(db, N).  Return the current
-	 * timeout value * if one is set.  If no busy handler
-	 * or a different busy handler is set * then 0 is
-	 * returned.  Setting the busy_timeout to 0 or negative *
-	 * disables the timeout.
-	 */
-	/* case PragTyp_BUSY_TIMEOUT */
-	default:{
-			assert(pPragma->ePragTyp == PragTyp_BUSY_TIMEOUT);
-			if (zRight) {
-				sqlite3_busy_timeout(db, sqlite3Atoi(zRight));
-			}
-			returnSingleInt(v, db->busyTimeout);
-			break;
-		}
-	}			/* End of the PRAGMA switch */
+	default:
+		unreachable();
+	}
 
 	/* The following block is a no-op unless SQLITE_DEBUG is
 	 * defined. Its only * purpose is to execute assert()
diff --git a/src/box/sql/pragma.h b/src/box/sql/pragma.h
index 168c70561..2857390c4 100644
--- a/src/box/sql/pragma.h
+++ b/src/box/sql/pragma.h
@@ -5,7 +5,6 @@
  */
 
 /* The various pragma types */
-#define PragTyp_BUSY_TIMEOUT                   1
 #define PragTyp_CASE_SENSITIVE_LIKE            2
 #define PragTyp_COLLATION_LIST                 3
 #define PragTyp_FLAG                           5
@@ -67,8 +66,6 @@ static const char *const pragCName[] = {
 	/*  26 */ "on_update",
 	/*  27 */ "on_delete",
 	/*  28 */ "match",
-	/* Used by: busy_timeout */
-	/*  29 */ "timeout",
 };
 
 /* Definitions of all built-in pragmas */
@@ -85,11 +82,6 @@ typedef struct PragmaName {
  * to be sorted. For more info see pragma_locate function.
  */
 static const PragmaName aPragmaName[] = {
-	{ /* zName:     */ "busy_timeout",
-	 /* ePragTyp:  */ PragTyp_BUSY_TIMEOUT,
-	 /* ePragFlg:  */ PragFlg_Result0,
-	 /* ColNames:  */ 29, 1,
-	 /* iArg:      */ 0},
 	{ /* zName:     */ "case_sensitive_like",
 	 /* ePragTyp:  */ PragTyp_CASE_SENSITIVE_LIKE,
 	 /* ePragFlg:  */ PragFlg_NoColumns,
diff --git a/src/box/sql/sqliteInt.h b/src/box/sql/sqliteInt.h
index db7a20aee..1633c1a35 100644
--- a/src/box/sql/sqliteInt.h
+++ b/src/box/sql/sqliteInt.h
@@ -329,7 +329,6 @@ struct sqlite3_vfs {
 		      int flags, int *pOutFlags);
 	int (*xDelete) (sqlite3_vfs *, const char *zName, int syncDir);
 	int (*xRandomness) (sqlite3_vfs *, int nByte, char *zOut);
-	int (*xSleep) (sqlite3_vfs *, int microseconds);
 	int (*xCurrentTime) (sqlite3_vfs *, double *);
 	int (*xGetLastError) (sqlite3_vfs *, int, char *);
 	/*
@@ -825,7 +824,6 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_VFSNAME                11
 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE    12
 #define SQLITE_FCNTL_PRAGMA                 13
-#define SQLITE_FCNTL_BUSYHANDLER            14
 #define SQLITE_FCNTL_TEMPFILENAME           15
 #define SQLITE_FCNTL_MMAP_SIZE              16
 #define SQLITE_FCNTL_TRACE                  17
@@ -835,9 +833,6 @@ struct sqlite3_io_methods {
 int
 sqlite3_os_init(void);
 
-int
-sqlite3_busy_timeout(sqlite3 *, int ms);
-
 sqlite3_int64
 sqlite3_soft_heap_limit64(sqlite3_int64 N);
 
@@ -1310,22 +1305,6 @@ extern const int sqlite3one;
 #undef WHERETRACE_ENABLED
 #endif
 
-/*
- * An instance of the following structure is used to store the busy-handler
- * callback for a given sqlite handle.
- *
- * The sqlite.busyHandler member of the sqlite struct contains the busy
- * callback for the database handle. Each pager opened via the sqlite
- * handle is passed a pointer to sqlite.busyHandler. The busy-handler
- * callback is currently invoked only from within pager.c.
- */
-typedef struct BusyHandler BusyHandler;
-struct BusyHandler {
-	int (*xFunc) (void *, int);	/* The busy callback */
-	void *pArg;		/* First arg to busy callback */
-	int nBusy;		/* Incremented with each busy call */
-};
-
 /*
  * A convenience macro that returns the number of elements in
  * an array.
@@ -1554,8 +1533,6 @@ struct sqlite3 {
 	unsigned nProgressOps;	/* Number of opcodes for progress callback */
 #endif
 	Hash aFunc;		/* Hash table of connection functions */
-	BusyHandler busyHandler;	/* Busy callback */
-	int busyTimeout;	/* Busy handler timeout, in msec */
 	int *pnBytesFreed;	/* If not NULL, increment this in DbFree() */
 };
 
diff --git a/src/box/sql/vdbe.c b/src/box/sql/vdbe.c
index 9fc362f0a..481727b5e 100644
--- a/src/box/sql/vdbe.c
+++ b/src/box/sql/vdbe.c
@@ -666,7 +666,6 @@ int sqlite3VdbeExec(Vdbe *p)
 	p->iCurrentTime = 0;
 	assert(p->explain==0);
 	p->pResultSet = 0;
-	db->busyHandler.nBusy = 0;
 	if (db->u1.isInterrupted) goto abort_due_to_interrupt;
 	sqlite3VdbeIOTraceSql(p);
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
-- 
2.17.1