optimize the support for SDB

wal file can be kept, and reopened when the system restarts

src/wal/src/walMain.c

@@ -35,6 +35,7 @@
 #define wPrint(...) {tprintf("WAL ", 255, __VA_ARGS__);}
 
 typedef struct {
+  uint64_t version;
   int      fd;
   int      keep;
   int      level;
@@ -50,9 +51,8 @@ int wDebugFlag = 135;
 
 static uint32_t walSignature = 0xFAFBFDFE;
 static int walHandleExistingFiles(const char *path);
-static int walRestoreWalFile(const char *name, void *pVnode, FWalWrite writeFp);
+static int walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp);
 static int walRemoveWalFiles(const char *path);
-static int walMoveOldWalFilesBack(const char *path);
 
 void *walOpen(const char *path, const SWalCfg *pCfg) {
   SWal *pWal = calloc(sizeof(SWal), 1);
@@ -69,6 +69,8 @@ void *walOpen(const char *path, const SWalCfg *pCfg) {
 
   if (access(path, F_OK) != 0) mkdir(path, 0755);
   
+  if (pCfg->keep == 1) return pWal;
+
   if (walHandleExistingFiles(path) == 0) 
     walRenew(pWal);
 
@@ -155,6 +157,7 @@ int walWrite(void *handle, SWalHead *pHead) {
 
   // no wal  
   if (pWal->level == TAOS_WAL_NOLOG) return 0;
+  if (pHead->version <= pWal->version) return 0;
 
   pHead->signature = walSignature;
   taosCalcChecksumAppend(0, (uint8_t *)pHead, sizeof(SWalHead));
@@ -163,7 +166,9 @@ int walWrite(void *handle, SWalHead *pHead) {
   if(write(pWal->fd, pHead, contLen) != contLen) {
     wError("wal:%s, failed to write(%s)", pWal->name, strerror(errno));
     code = -1;
-  }  
+  } else {
+    pWal->version = pHead->version;
+  }
 
   return code;
 }
@@ -185,7 +190,10 @@ int walRestore(void *handle, void *pVnode, int (*writeFp)(void *, void *, int))
 
   int   plen = strlen(walPrefix);
   char  opath[TSDB_FILENAME_LEN+5];
-  sprintf(opath, "%s/old", pWal->path);
+   
+  int slen = sprintf(opath, "%s", pWal->path);
+  if ( pWal->keep == 0) 
+    strcpy(opath+slen, "/old");
 
   // is there old directory?
   if (access(opath, F_OK)) return 0; 
@@ -200,6 +208,8 @@ int walRestore(void *handle, void *pVnode, int (*writeFp)(void *, void *, int))
     }
   }
 
+  if (count == 0) return 0;
+
   if ( count != (maxId-minId+1) ) {
     wError("wal:%s, messed up, count:%d max:%d min:%d", opath, count, maxId, minId);
     code = -1;
@@ -207,21 +217,29 @@ int walRestore(void *handle, void *pVnode, int (*writeFp)(void *, void *, int))
     wTrace("wal:%s, %d files will be restored", opath, count);
 
     for (index = minId; index<=maxId; ++index) {
-      sprintf(pWal->name, "%s/old/%s%d", pWal->path, walPrefix, index);
-      code = walRestoreWalFile(pWal->name, pVnode, writeFp);
+      sprintf(pWal->name, "%s/%s%d", opath, walPrefix, index);
+      code = walRestoreWalFile(pWal, pVnode, writeFp);
       if (code < 0) break;
     }
   }
 
   if (code == 0) {
-    if (pWal->keep) {
-      code = walMoveOldWalFilesBack(pWal->path);
-    } else {
+    if (pWal->keep == 0) {
       code = walRemoveWalFiles(opath);
-    }
-    if (code == 0) {
-      if (remove(opath) < 0) {
-        wError("wal:%s, failed to remove directory(%s)", opath, strerror(errno));
+      if (code == 0) {
+        if (remove(opath) < 0) {
+          wError("wal:%s, failed to remove directory(%s)", opath, strerror(errno));
+          code = -1;
+        }
+      }
+    } else { 
+      // open the existing WAL file in append mode
+      pWal->num = count;
+      pWal->id = maxId;
+      sprintf(pWal->name, "%s/%s%d", opath, walPrefix, maxId);
+      pWal->fd = open(pWal->name, O_WRONLY | O_CREAT | O_APPEND, S_IRWXU | S_IRWXG | S_IRWXO);
+      if (pWal->fd < 0) {
+        wError("wal:%s, failed to open file(%s)", pWal->name, strerror(errno));
         code = -1;
       }
     }
@@ -257,8 +275,9 @@ int walGetWalFile(void *handle, char *name, uint32_t *index) {
   return code;
 }  
 
-static int walRestoreWalFile(const char *name, void *pVnode, FWalWrite writeFp) {
-  int code = 0;
+static int walRestoreWalFile(SWal *pWal, void *pVnode, FWalWrite writeFp) {
+  int   code = 0;
+  char *name = pWal->name;
 
   char *buffer = malloc(1024000);  // size for one record
   if (buffer == NULL) return -1;
@@ -294,10 +313,11 @@ static int walRestoreWalFile(const char *name, void *pVnode, FWalWrite writeFp)
       break;
     }
 
-    // write into queue
+    if (pWal->keep) pWal->version = pHead->version;
     (*writeFp)(pVnode, pHead, TAOS_QTYPE_WAL);
   }
 
+  close(fd);
   free(buffer);
 
   return code;
@@ -370,40 +390,3 @@ static int walRemoveWalFiles(const char *path) {
   return code;
 }
 
-int walMoveOldWalFilesBack(const char *path) {
-  char   oname[TSDB_FILENAME_LEN * 3];
-  char   nname[TSDB_FILENAME_LEN * 3];
-  char   opath[TSDB_FILENAME_LEN];
-  struct dirent *ent;
-  int    plen = strlen(walPrefix);
-  int    code = 0;
-
-  sprintf(opath, "%s/old", path);
-
-  if (access(opath, F_OK) == 0) {
-    // move all old files to wal directory
-    int count = 0;
-
-    DIR   *dir = opendir(opath);
-    while ((ent = readdir(dir))!= NULL) {  
-      if ( strncmp(ent->d_name, walPrefix, plen) == 0) {
-        sprintf(oname, "%s/%s", opath, ent->d_name);
-        sprintf(nname, "%s/%s", path, ent->d_name);
-        if (rename(oname, nname) < 0) {
-          wError("wal:%s, failed to move to new:%s", oname, nname);
-          code = -1;
-          break;
-        } 
-
-        count++;
-      }
-    }
-
-    wTrace("wal:%s, %d old files are move back for keep option is set", path, count);
-    closedir(dir);
-  }
-  
-  return code;
-}
-
-

src/wal/test/waltest.c

@@ -29,8 +29,6 @@ int writeToQueue(void *pVnode, void *data, int type) {
     ver = pHead->version;
 
   walWrite(pWal, pHead);
-  
-  free(pHead);
 
   return 0;
 }
@@ -42,6 +40,7 @@ int main(int argc, char *argv[]) {
   int  total = 5;
   int  rows = 10000;
   int  size = 128;
+  int  keep = 0;
 
   for (int i=1; i<argc; ++i) {
     if (strcmp(argv[i], "-p")==0 && i < argc-1) {
@@ -52,6 +51,8 @@ int main(int argc, char *argv[]) {
       level = atoi(argv[++i]);
     } else if (strcmp(argv[i], "-r")==0 && i < argc-1) {
       rows = atoi(argv[++i]);
+    } else if (strcmp(argv[i], "-k")==0 && i < argc-1) {
+      keep = atoi(argv[++i]);
     } else if (strcmp(argv[i], "-t")==0 && i < argc-1) {
       total = atoi(argv[++i]);
     } else if (strcmp(argv[i], "-s")==0 && i < argc-1) {
@@ -67,6 +68,7 @@ int main(int argc, char *argv[]) {
       printf("  [-l level]: log level, default is:%d\n", level);
       printf("  [-t total]: total wal files, default is:%d\n", total);
       printf("  [-r rows]: rows of records per wal file, default is:%d\n", rows);
+      printf("  [-k keep]: keep the wal after closing, default is:%d\n", keep);
       printf("  [-v version]: initial version, default is:%ld\n", ver);
       printf("  [-d debugFlag]: debug flag, default:%d\n", ddebugFlag);
       printf("  [-h help]: print out this help\n\n");
@@ -79,6 +81,7 @@ int main(int argc, char *argv[]) {
   SWalCfg walCfg;
   walCfg.commitLog = level;
   walCfg.wals = max;
+  walCfg.keep = keep;
 
   pWal = walOpen(path, &walCfg);
   if (pWal == NULL) {