first draft for WAL

src/vnode/wal/CMakeLists.txt

+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+INCLUDE_DIRECTORIES(inc)
+
 AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR}/src SRC)
 
-ADD_LIBRARY(wal ${SRC})
-TARGET_INCLUDE_DIRECTORIES(wal PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/inc)
\ No newline at end of file
+ADD_LIBRARY(twal ${SRC})
+TARGET_LINK_LIBRARIES(twal tutil)
+
+ADD_SUBDIRECTORY(test)
+

src/vnode/wal/inc/vnodeWal.h → src/vnode/wal/inc/twal.h

@@ -14,19 +14,36 @@
  */
 #ifndef _TD_WAL_H_
 #define _TD_WAL_H_
-#include <stdint.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-typedef void walh;  // WAL HANDLE
+#define TAOS_WAL_NOLOG   0
+#define TAOS_WAL_WRITE   1
+#define TAOS_WAL_FSYNC   2
+ 
+typedef struct {
+  uint32_t  signature;
+  uint32_t  cksum;
+  int8_t    msgType;
+  int8_t    reserved[3];
+  int32_t   len;
+  uint64_t  version;
+  char      cont[];
+} SWalHead;
+
+typedef void* twal_h;  // WAL HANDLE
+
+twal_h  walOpen(char *path, int max, int level);
+void    walClose(twal_h);
+int     walRenew(twal_h);
+int     walWrite(twal_h, SWalHead *);
+void    walFsync(twal_h);
+int     walRestore(twal_h, void *pVnode, int (*writeFp)(void *ahandle, void *pWalHead));
+
+extern int wDebugFlag;
 
-walh *vnodeOpenWal(int vnode, uint8_t op);
-int   vnodeCloseWal(walh *pWal);
-int   vnodeRenewWal(walh *pWal);
-int   vnodeWriteWal(walh *pWal, void *cont, int contLen);
-int   vnodeSyncWal(walh *pWal);
 
 #ifdef __cplusplus
 }

src/vnode/wal/src/vnodeWal.c

-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-#include <stdlib.h>
-
-#include "vnodeWal.h"
-
-typedef struct {
-  /* TODO */
-} SWal;
-
-walh *vnodeOpenWal(int vnode, uint8_t op) { return NULL; }
-int   vnodeCloseWal(walh *pWal) { return 0; }
-int   vnodeRenewWal(walh *pWal) { return 0; }
-int   vnodeWriteWal(walh *pWal, void *cont, int contLen) { return 0; }
-int   vnodeSyncWal(walh *pWal) { return 0; }
\ No newline at end of file

src/vnode/wal/src/walMain.c

+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <fcntl.h> 
+
+#include "os.h"
+#include "tlog.h"
+#include "tutil.h"
+#include "twal.h"
+
+#define walPrefix "wal"
+#define wError(...) if (wDebugFlag & DEBUG_ERROR) {tprintf("ERROR WAL ", wDebugFlag, __VA_ARGS__);}
+#define wWarn(...) if (wDebugFlag & DEBUG_WARN) {tprintf("WARN WAL ", wDebugFlag, __VA_ARGS__);}
+#define wTrace(...) if (wDebugFlag & DEBUG_TRACE) {tprintf("WAL ", wDebugFlag, __VA_ARGS__);}
+#define wPrint(...) {tprintf("WAL ", 255, __VA_ARGS__);}
+
+typedef struct {
+  int      fd;
+  int      level;
+  int      max;  // maximum number of wal files
+  uint32_t id;   // increase continuously
+  int      num;  // number of wal files
+  char     path[TSDB_FILENAME_LEN];
+  char     name[TSDB_FILENAME_LEN];
+} SWal;
+
+int wDebugFlag = 135;
+
+static uint32_t walSignature = 0xFAFBFDFE;
+static int walHandleExistingFiles(char *path);
+static int walRestoreWalFile(char *name, void *pVnode, int (*writeFp)(void *, void *));
+static int walRemoveWalFiles(char *path);
+
+void *walOpen(char *path, int max, int level) {
+  SWal *pWal = calloc(sizeof(SWal), 1);
+  if (pWal == NULL) return NULL;
+
+  pWal->fd = -1;
+  pWal->max = max;
+  pWal->id = 0;
+  pWal->num = 0;
+  pWal->level = level;
+  strcpy(pWal->path, path);
+
+  if (access(path, F_OK) != 0) mkdir(path, 0755);
+  
+  if (walHandleExistingFiles(path) == 0) 
+    walRenew(pWal);
+
+  if (pWal->fd <0) {
+    wError("wal:%s, failed to open", path);
+    free(pWal);
+    pWal = NULL;
+  }
+
+  return pWal;
+}
+
+void walClose(void *handle) {
+ 
+  SWal *pWal = (SWal *)handle;
+  
+  close(pWal->fd);
+
+  // remove all files in the directory
+  for (int i=0; i<pWal->num; ++i) {
+    sprintf(pWal->name, "%s/%s%010d", pWal->path, walPrefix, pWal->id-i);
+    if (remove(pWal->name) <0) {
+      wError("wal:%s, failed to remove", pWal->name);
+    } else {
+      wTrace("wal:%s, it is removed", pWal->name);
+    }
+  }
+}
+
+int walRenew(twal_h handle) {
+  SWal *pWal = (SWal *)handle;
+  
+  if (pWal->fd >=0) {
+    close(pWal->fd);
+    pWal->id++;
+    wTrace("wal:%s, it is closed", pWal->name);
+  }
+
+  sprintf(pWal->name, "%s/%s%010d", pWal->path, walPrefix, pWal->id);
+  pWal->fd = open(pWal->name, O_WRONLY | O_CREAT, S_IRWXU | S_IRWXG | S_IRWXO);
+  if (pWal->fd < 0) {
+    wError("wal:%d, failed to open(%s)", pWal->name, strerror(errno));
+    return -1;
+  }
+
+  wTrace("wal:%s, it is open", pWal->name);
+
+  pWal->num++;
+  if (pWal->num > pWal->max) {
+    // remove the oldest wal file
+    char name[TSDB_FILENAME_LEN];
+    sprintf(name, "%s/%s%010d", pWal->path, walPrefix, pWal->id - pWal->max);
+    if (remove(name) <0) {
+      wError("wal:%s, failed to remove(%s)", name, strerror(errno));
+    } else {
+      wTrace("wal:%s, it is removed", name);
+    }
+
+    pWal->num--;
+  }  
+  
+  return 0;
+}
+
+int walWrite(void *handle, SWalHead *pHead) {
+  SWal *pWal = (SWal *)handle;
+  int   code = 0;
+
+  // no wal  
+  if (pWal->level == TAOS_WAL_NOLOG) return 0;
+
+  pHead->signature = walSignature;
+  int contLen = pHead->len + sizeof(SWalHead);
+
+  if(write(pWal->fd, pHead, contLen) != contLen) {
+    wError("wal:%s, failed to write(%s)", pWal->name, strerror(errno));
+    code = -1;
+  }  
+
+  return code;
+}
+
+void walFsync(void *handle) {
+
+  SWal *pWal = (SWal *)handle;
+
+  if (pWal->level == TAOS_WAL_FSYNC) 
+    fsync(pWal->fd);
+}
+
+int walRestore(void *handle, void *pVnode, int (*writeFp)(void *, void *)) {
+  SWal    *pWal = (SWal *)handle;
+  int      code = 0;
+  struct   dirent *ent;
+  int      count = 0;
+  uint32_t maxId = 0, minId = -1, index =0;
+
+  int   plen = strlen(walPrefix);
+  char  opath[TSDB_FILENAME_LEN];
+  sprintf(opath, "%s/old", pWal->path);
+
+  // is there old directory?
+  if (access(opath, F_OK)) return 0; 
+
+  DIR *dir = opendir(opath);
+  while ((ent = readdir(dir))!= NULL) {
+    if ( strncmp(ent->d_name, walPrefix, plen) == 0) {
+      index = atol(ent->d_name + plen);
+      if (index > maxId) maxId = index;
+      if (index < minId) minId = index;
+      count++;
+    }
+  }
+
+  if ( count != (maxId-minId+1) ) {
+    wError("wal:%s, messed up, count:%d max:%ld min:%ld", opath, count, maxId, minId);
+    code = -1;
+  } else {
+    wTrace("wal:%s, %d files will be restored", opath, count);
+
+    for (index = minId; index<=maxId; ++index) {
+      sprintf(pWal->name, "%s/old/%s%010d", pWal->path, walPrefix, index);
+      code = walRestoreWalFile(pWal->name, pVnode, writeFp);
+      if (code < 0) break;
+    }
+  }
+
+  if (code == 0) {
+    code = walRemoveWalFiles(opath);
+    if (code == 0) {
+      if (remove(opath) < 0) {
+        wError("wal:%s, failed to remove directory(%s)", opath, strerror(errno));
+        code = -1;
+      }
+    }
+  }
+
+  closedir(dir);
+
+  return code;
+}
+
+static int walRestoreWalFile(char *name, void *pVnode, int (*writeFp)(void *, void *)) {
+  SWalHead walHead;
+  int      code = -1;
+
+  int fd = open(name, O_RDONLY);
+  if (fd < 0) {
+    wError("wal:%s, failed to open for restore(%s)", name, strerror(errno));
+    return -1;
+  }
+
+  wTrace("wal:%s, start to restore", name);
+
+  while (1) {
+    int ret = read(fd, &walHead, sizeof(walHead));
+    if ( ret == 0) { code = 0; break;}  
+
+    if (ret != sizeof(walHead)) {
+      wError("wal:%s, failed to read(%s)", name, strerror(errno));
+      break;
+    }
+
+    if (walHead.signature != walSignature) {
+      wError("wal:%s, file is messed up, signature:", name, walHead.signature);
+      break;
+    }
+
+    char *buffer = malloc(sizeof(SWalHead) + walHead.len);
+    memcpy(buffer, &walHead, sizeof(walHead));
+
+    ret = read(fd, buffer+sizeof(walHead), walHead.len);
+    if ( ret != walHead.len) {
+      wError("wal:%s, failed to read(%s)", name, strerror(errno));
+      break;
+    }
+
+    // write into queue
+    (*writeFp)(pVnode, buffer);
+  }
+
+  return code;
+}
+
+int walHandleExistingFiles(char *path) {
+  int    code = 0;
+  char   oname[TSDB_FILENAME_LEN];
+  char   nname[TSDB_FILENAME_LEN];
+  char   opath[TSDB_FILENAME_LEN];
+
+  sprintf(opath, "%s/old", path);
+
+  struct dirent *ent;
+  DIR   *dir = opendir(path);
+  int    plen = strlen(walPrefix);
+
+  if (access(opath, F_OK) == 0) {
+    // old directory is there, it means restore process is not finished
+    walRemoveWalFiles(path);
+
+  } else {
+    // move all files to old directory
+    int count = 0;
+    while ((ent = readdir(dir))!= NULL) {  
+      if ( strncmp(ent->d_name, walPrefix, plen) == 0) {
+        if (access(opath, F_OK) != 0) mkdir(opath, 0755);
+
+        sprintf(oname, "%s/%s", path, ent->d_name);
+        sprintf(nname, "%s/old/%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 files are moved for restoration", path, count);
+  }
+  
+  closedir(dir);
+  return code;
+}
+
+static int walRemoveWalFiles(char *path) {
+  int    plen = strlen(walPrefix);
+  char   name[TSDB_FILENAME_LEN];
+  int    code = 0;
+
+  if (access(path, F_OK) != 0) return 0;
+
+  struct dirent *ent;
+  DIR   *dir = opendir(path);
+
+  while ((ent = readdir(dir))!= NULL) {
+    if ( strncmp(ent->d_name, walPrefix, plen) == 0) {
+      sprintf(name, "%s/%s", path, ent->d_name);
+      if (remove(name) <0) {
+        wError("wal:%s, failed to remove(%s)", name, strerror(errno));
+        code = -1; break;
+      }
+    }
+  } 
+
+  closedir(dir);
+
+  return code;
+}
+
+

src/vnode/wal/test/CMakeLists.txt

+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
+  INCLUDE_DIRECTORIES(${TD_OS_DIR}/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/inc)
+  INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/util/inc)
+  INCLUDE_DIRECTORIES(../inc)
+
+  LIST(APPEND WALTEST_SRC ./waltest.c)
+  ADD_EXECUTABLE(waltest ${WALTEST_SRC})
+  TARGET_LINK_LIBRARIES(waltest twal)
+
+ENDIF ()
+
+

src/vnode/wal/test/waltest.c

+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+//#define _DEFAULT_SOURCE
+#include <stdint.h>
+#include "tlog.h"
+#include "twal.h"
+
+int64_t  ver = 0;
+void    *pWal = NULL;
+
+int writeToQueue(void *pVnode, void *data) {
+  SWalHead *pHead = (SWalHead *)data;
+
+  // do nothing
+  if (pHead->version > ver)
+    ver = pHead->version;
+
+  walWrite(pWal, pHead);
+  
+  free(data);
+
+  return 0;
+}
+
+int main(int argc, char *argv[]) {
+  char path[128] = "/home/jhtao/test/wal";
+  int  max = 3;
+  int  level = 2;
+  int  total = 5;
+  int  rows = 10000;
+  int  size = 128;
+
+  for (int i=1; i<argc; ++i) {
+    if (strcmp(argv[i], "-p")==0 && i < argc-1) {
+      strcpy(path, argv[++i]);
+    } else if (strcmp(argv[i], "-m")==0 && i < argc-1) {
+      max = atoi(argv[++i]);
+    } else if (strcmp(argv[i], "-l")==0 && i < argc-1) {
+      level = atoi(argv[++i]);
+    } else if (strcmp(argv[i], "-r")==0 && i < argc-1) {
+      rows = 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) {
+      size = atoi(argv[++i]);
+    } else if (strcmp(argv[i], "-v")==0 && i < argc-1) {
+      ver = atoll(argv[++i]);
+    } else if (strcmp(argv[i], "-d")==0 && i < argc-1) {
+      ddebugFlag = atoi(argv[++i]);
+    } else {
+      printf("\nusage: %s [options] \n", argv[0]);
+      printf("  [-p path]: wal file path default is:%s\n", path);
+      printf("  [-m max]: max wal files, default is:%d\n", max);
+      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("  [-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");
+      exit(0);
+    }
+  } 
+
+  taosInitLog("wal.log", 100000, 10);
+
+  pWal = walOpen(path, max, level);
+  if (pWal == NULL) {
+    printf("failed to open wal\n");
+    exit(-1);
+  }
+
+  int ret = walRestore(pWal, NULL, writeToQueue);
+  if (ret <0) {
+    printf("failed to restore wal\n");
+    exit(-1);
+  }
+
+  printf("version starts from:%ld\n", ver);
+  
+  int contLen = sizeof(SWalHead) + size;
+  SWalHead *pHead = (SWalHead *) malloc(contLen);
+
+  for (int i=0; i<total; ++i) {
+    for (int k=0; k<rows; ++k) {
+      pHead->version = ++ver;
+      walWrite(pWal, pHead);
+    }
+       
+    printf("renew a wal, i:%d\n", i);
+    walRenew(pWal);
+  }
+
+  printf("%d wal files are written\n", total);
+  getchar();
+
+  walClose(pWal);
+
+  return 0;
+}