From 6d29a4fe5be41d63d7c2ba8a82ad9777a4acc39f Mon Sep 17 00:00:00 2001
From: dan <Dan Kennedy>
Date: Thu, 22 Apr 2021 17:40:28 +0000
Subject: [PATCH] Add the sqlite3session_object_config() API. Current used to
 enable/disable collecting data for sqlite3session_changeset_size().

FossilOrigin-Name: 4d5fd2151e024d11289b6c4fbce2996d8d07b2b5a1c953ef895c237e79d3aa55
---
 ext/session/sessionsize.test | 23 +++++++++++++++++++
 ext/session/sqlite3session.c | 43 +++++++++++++++++++++++++++++++-----
 ext/session/sqlite3session.h | 27 ++++++++++++++++++++++
 ext/session/test_session.c   | 26 ++++++++++++++++++++++
 manifest                     | 21 ++++++++----------
 manifest.uuid                |  2 +-
 6 files changed, 124 insertions(+), 18 deletions(-)

diff --git a/ext/session/sessionsize.test b/ext/session/sessionsize.test
index 8347097e96..04d05514db 100644
--- a/ext/session/sessionsize.test
+++ b/ext/session/sessionsize.test
@@ -104,5 +104,28 @@ do_changeset_size_test 2.7 {
   INSERT INTO t3 VALUES(1,2,3,4);
 }
 
+#-------------------------------------------------------------------------
+reset_db
+
+do_execsql_test 3.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
+}
+
+do_test 3.1 {
+  sqlite3session S db main
+  S object_config_size -1
+} 1
+
+do_test 3.2.1 { S object_config_size 0  } 0
+do_test 3.2.2 { S object_config_size -1 } 0
+do_test 3.2.3 { S object_config_size 1  } 1
+do_test 3.2.4 { S object_config_size -1 } 1
+
+do_test 3.3 { S attach t1 } {}
+do_test 3.4 { S object_config_size 1  } {SQLITE_MISUSE}
+do_test 3.4 { S object_config_size -1 } {1}
+
+S delete
+
 finish_test
 
diff --git a/ext/session/sqlite3session.c b/ext/session/sqlite3session.c
index 077a6e0900..1f6c58b4db 100644
--- a/ext/session/sqlite3session.c
+++ b/ext/session/sqlite3session.c
@@ -42,6 +42,7 @@ struct SessionHook {
 struct sqlite3_session {
   sqlite3 *db;                    /* Database handle session is attached to */
   char *zDb;                      /* Name of database session is attached to */
+  int bEnableSize;                /* True if changeset_size() enabled */
   int bEnable;                    /* True if currently recording */
   int bIndirect;                  /* True if all changes are indirect */
   int bAutoAttach;                /* True to auto-attach tables */
@@ -1124,9 +1125,11 @@ static int sessionInitTable(sqlite3_session *pSession, SessionTable *pTab){
         pTab->bStat1 = 1;
       }
 
-      pSession->nMaxChangesetSize += (
-        1 + sessionVarintLen(pTab->nCol) + pTab->nCol + strlen(pTab->zName) + 1
-      );
+      if( pSession->bEnableSize ){
+        pSession->nMaxChangesetSize += (
+          1 + sessionVarintLen(pTab->nCol) + pTab->nCol + strlen(pTab->zName)+1
+        );
+      }
     }
   }
   return (pSession->rc || pTab->abPK==0);
@@ -1411,7 +1414,9 @@ static void sessionPreupdateOneChange(
     }
 
     assert( rc==SQLITE_OK );
-    rc = sessionUpdateMaxSize(op, pSession, pTab, pC);
+    if( pSession->bEnableSize ){
+      rc = sessionUpdateMaxSize(op, pSession, pTab, pC);
+    }
   }
 
 
@@ -2627,7 +2632,9 @@ int sqlite3session_changeset(
   void **ppChangeset              /* OUT: Buffer containing changeset */
 ){
   int rc = sessionGenerateChangeset(pSession, 0, 0, 0, pnChangeset,ppChangeset);
-  assert( rc || pnChangeset==0 || *pnChangeset<=pSession->nMaxChangesetSize );
+  assert( rc || pnChangeset==0 
+       || pSession->bEnableSize==0 || *pnChangeset<=pSession->nMaxChangesetSize 
+  );
   return rc;
 }
 
@@ -2720,6 +2727,32 @@ sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession){
   return pSession->nMalloc;
 }
 
+/*
+** Configure the session object passed as the first argument.
+*/
+int sqlite3session_object_config(sqlite3_session *pSession, int op, void *pArg){
+  int rc = SQLITE_OK;
+  switch( op ){
+    case SQLITE_SESSION_OBJCONFIG_SIZE: {
+      int iArg = *(int*)pArg;
+      if( iArg>=0 ){
+        if( pSession->pTable ){
+          rc = SQLITE_MISUSE;
+        }else{
+          pSession->bEnableSize = (iArg!=0);
+        }
+      }
+      *(int*)pArg = pSession->bEnableSize;
+      break;
+    }
+
+    default:
+      rc = SQLITE_MISUSE;
+  }
+
+  return rc;
+}
+
 /*
 ** Return the maximum size of sqlite3session_changeset() output.
 */
diff --git a/ext/session/sqlite3session.h b/ext/session/sqlite3session.h
index 78d25ba0f3..43a03fc04d 100644
--- a/ext/session/sqlite3session.h
+++ b/ext/session/sqlite3session.h
@@ -79,6 +79,33 @@ int sqlite3session_create(
 */
 void sqlite3session_delete(sqlite3_session *pSession);
 
+/*
+** CAPIREF: Conigure a Session Object
+** METHOD: sqlite3_session
+*/
+int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
+
+/*
+** CAPI3REF: Arguments for sqlite3session_object_config()
+**
+** The following values may passed as the the 4th parameter to
+** [sqlite3session_object_config].
+**
+** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
+**   This option is used to set, clear or query the flag that enables
+**   the [sqlite3session_changeset_size()] API. Because it imposes some
+**   computational overhead, this API is disabled by default. Argument
+**   pArg must point to a value of type (int). If the value is initially
+**   0, then the sqlite3session_changeset_size() API is disabled. If it
+**   is greater than 0, then the same API is enabled. Or, if the initial
+**   value is less than zero, no change is made. In all cases the (int)
+**   variable is set to 1 if the sqlite3session_changeset_size() API is
+**   enabled following the current call, or 0 otherwise.
+**
+**   It is an error (SQLITE_MISUSE) to attempt to modify this setting after 
+**   the first table has been attached to the session object.
+*/
+#define SQLITE_SESSION_OBJCONFIG_SIZE 1
 
 /*
 ** CAPI3REF: Enable Or Disable A Session Object
diff --git a/ext/session/test_session.c b/ext/session/test_session.c
index b7c96b2657..f2fc77eee3 100644
--- a/ext/session/test_session.c
+++ b/ext/session/test_session.c
@@ -247,6 +247,7 @@ static int SQLITE_TCLAPI test_session_cmd(
     { "diff",         2, "FROMDB TBL", }, /* 8 */
     { "memory_used",  0, "",           }, /* 9 */
     { "changeset_size", 0, "",         }, /* 10 */
+    { "object_config_size", 1, "INTEGER", }, /* 11 */
     { 0 }
   };
   int iSub;
@@ -364,6 +365,23 @@ static int SQLITE_TCLAPI test_session_cmd(
       Tcl_SetObjResult(interp, Tcl_NewWideIntObj(nSize));
       break;
     }
+    case 11: {
+      int rc;
+      int iArg;
+      if( Tcl_GetIntFromObj(interp, objv[2], &iArg) ){
+        return TCL_ERROR;
+      }
+      rc = sqlite3session_object_config(
+          pSession, SQLITE_SESSION_OBJCONFIG_SIZE, &iArg
+      );
+      if( rc!=SQLITE_OK ){
+        extern const char *sqlite3ErrName(int);
+        Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+      }else{
+        Tcl_SetObjResult(interp, Tcl_NewIntObj(iArg));
+      }
+      break;
+    }
   }
 
   return TCL_OK;
@@ -389,6 +407,7 @@ static int SQLITE_TCLAPI test_sqlite3session(
   Tcl_CmdInfo info;
   int rc;                         /* sqlite3session_create() return code */
   TestSession *p;                 /* New wrapper object */
+  int iArg = -1;
 
   if( objc!=4 ){
     Tcl_WrongNumArgs(interp, 1, objv, "CMD DB-HANDLE DB-NAME");
@@ -409,6 +428,13 @@ static int SQLITE_TCLAPI test_sqlite3session(
     return test_session_error(interp, rc, 0);
   }
 
+  /* Query the SQLITE_SESSION_OBJCONFIG_SIZE option to ensure that it
+  ** is clear by default. Then set it. */
+  sqlite3session_object_config(p->pSession,SQLITE_SESSION_OBJCONFIG_SIZE,&iArg);
+  assert( iArg==0 );
+  iArg = 1;
+  sqlite3session_object_config(p->pSession,SQLITE_SESSION_OBJCONFIG_SIZE,&iArg);
+
   Tcl_CreateObjCommand(
       interp, Tcl_GetString(objv[1]), test_session_cmd, (ClientData)p,
       test_session_del
diff --git a/manifest b/manifest
index 0c5737175f..11730cc2f5 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sthe\sexperimental\ssqlite3session_changeset_size()\sAPI.
-D 2021-04-21T20:52:17.903
+C Add\sthe\ssqlite3session_object_config()\sAPI.\sCurrent\sused\sto\senable/disable\scollecting\sdata\sfor\ssqlite3session_changeset_size().
+D 2021-04-22T17:40:28.167
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -453,12 +453,12 @@ F ext/session/sessioninvert.test 04075517a9497a80d39c495ba6b44f3982c7371129b89e2
 F ext/session/sessionmem.test f2a735db84a3e9e19f571033b725b0b2daf847f3f28b1da55a0c1a4e74f1de09
 F ext/session/sessionnoop.test a9366a36a95ef85f8a3687856ebef46983df399541174cb1ede2ee53b8011bc7
 F ext/session/sessionrebase.test ccfa716b23bd1d3b03217ee58cfd90c78d4b99f53e6a9a2f05e82363b9142810
-F ext/session/sessionsize.test 32ce42e9fed589276ef072b68c6f325e54ef7ef67c37ccd3ec8c822dd997f3c7
+F ext/session/sessionsize.test 6f644aff31c7f1e4871e9ff3542766e18da68fc7e587b83a347ea9820a002dd8
 F ext/session/sessionstat1.test 218d351cf9fcd6648f125a26b607b140310160184723c2666091b54450a68fb5
 F ext/session/sessionwor.test 6fd9a2256442cebde5b2284936ae9e0d54bde692d0f5fd009ecef8511f4cf3fc
-F ext/session/sqlite3session.c b205b57eecfb93aee23653ba4b07be6930afaa3760317c22ad9872a0bc451d3f
-F ext/session/sqlite3session.h 7d05ae78d03f778bf13f8160595b263d9436260137a8f50c78dc956f4d5121e2
-F ext/session/test_session.c b3d03f73b73d3794007392cf5a9bc27d1a2d3e970d500ab52026c726fa528142
+F ext/session/sqlite3session.c 703634ca25b4b903ae8ec25045802a8c8deca36a65d2b993c4bc8888f6d6c7ee
+F ext/session/sqlite3session.h 874b084ea97252a57ff1b79bb5da172ab4156f6302a8d3e3f5c88ce2748480d8
+F ext/session/test_session.c f433f68a8a8c64b0f5bc74dc725078f12483301ad4ae8375205eef790274a787
 F ext/userauth/sqlite3userauth.h 7f3ea8c4686db8e40b0a0e7a8e0b00fac13aa7a3
 F ext/userauth/user-auth.txt e6641021a9210364665fe625d067617d03f27b04
 F ext/userauth/userauth.c 7f00cded7dcaa5d47f54539b290a43d2e59f4b1eb5f447545fa865f002fc80cb
@@ -1914,10 +1914,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 6fe50dcc239d2d1fc2a38aa705f4c75cbe26b3e48d098537306d96d6a4005659
-R e870b873cf49a44c733c175dd8b4c0b8
-T *branch * session-changeset-size
-T *sym-session-changeset-size *
-T -sym-trunk *
+P b5564a6fd54875db1de884fdc0e5eeabcd6aa5595ad03a8a60843503e830a2d8
+R fa53b8d1cc3def8dc3ef8249968de9f0
 U dan
-Z c5add95d4af95f7f7d5a36a6c86b17cc
+Z 5eb2943cb766ada953003dbe5c9f5486
diff --git a/manifest.uuid b/manifest.uuid
index 3de85455ce..9cca027a55 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-b5564a6fd54875db1de884fdc0e5eeabcd6aa5595ad03a8a60843503e830a2d8
\ No newline at end of file
+4d5fd2151e024d11289b6c4fbce2996d8d07b2b5a1c953ef895c237e79d3aa55
\ No newline at end of file
-- 
2.39.5