extract KV store

src/util/inc/tkvstore.h

+/*
+ * 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/>.
+ */
+#ifndef _TD_KVSTORE_H_
+#define _TD_KVSTORE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+typedef int (*iterFunc)(void *, void *cont, int contLen);
+typedef void (*afterFunc)(void *);
+
+typedef struct {
+  int64_t size;
+  int64_t tombSize;
+  int64_t nRecords;
+  int64_t nDels;
+} SStoreInfo;
+
+typedef struct {
+  char *     fname;
+  int        fd;
+  char *     fsnap;
+  int        sfd;
+  char *     fnew;
+  int        nfd;
+  SHashObj * map;
+  iterFunc   iFunc;
+  afterFunc  aFunc;
+  void *     appH;
+  SStoreInfo info;
+} SKVStore;
+
+int       tdCreateKVStore(char *fname);
+int       tdDestroyKVStore();
+SKVStore *tdOpenKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void *appH);
+void      tdCloseKVStore(SKVStore *pStore);
+int       tdKVStoreStartCommit(SKVStore *pStore);
+int       tdUpdateRecordInKVStore(SKVStore *pStore, uint64_t uid, void *cont, int contLen);
+int       tdKVStoreEndCommit(SKVStore *pStore);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
\ No newline at end of file

src/util/src/tkvstore.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 <errno.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "hash.h"
+#include "os.h"
+#include "taoserror.h"
+#include "tchecksum.h"
+#include "tcoding.h"
+#include "tkvstore.h"
+#include "tulog.h"
+
+#define TD_KVSTORE_HEADER_SIZE 512
+#define TD_KVSTORE_MAJOR_VERSION 1
+#define TD_KVSTORE_MAINOR_VERSION 0
+#define TD_KVSTORE_SNAP_SUFFIX ".snap"
+#define TD_KVSTORE_NEW_SUFFIX ".new"
+
+static int       tdInitKVStoreHeader(int fd, char *fname);
+static void *    tdEncodeStoreInfo(void *buf, SStoreInfo *pInfo);
+// static void *    tdDecodeStoreInfo(void *buf, SStoreInfo *pInfo);
+static SKVStore *tdNewKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void *appH);
+static char *    tdGetKVStoreSnapshotFname(char *fdata);
+static char *    tdGetKVStoreNewFname(char *fdata);
+static void      tdFreeKVStore(SKVStore *pStore);
+
+int tdCreateKVStore(char *fname) {
+  char *tname = strdup(fname);
+  if (tname == NULL) return TSDB_CODE_SERV_OUT_OF_MEMORY;
+
+  int fd = open(fname, O_RDWR | O_CREAT, 0755);
+  if (fd < 0) {
+    uError("failed to open file %s since %s", fname, strerror(errno));
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  int code = tdInitKVStoreHeader(fd, fname);
+  if (code != TSDB_CODE_SUCCESS) return code;
+
+  if (fsync(fd) < 0) {
+    uError("failed to fsync file %s since %s", fname, strerror(errno));
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  if (close(fd) < 0) {
+    uError("failed to close file %s since %s", fname, strerror(errno));
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+SKVStore *tdOpenKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void *appH) {
+  SKVStore *pStore = tdNewKVStore(fname, iFunc, aFunc, appH);
+  if (pStore == NULL) return NULL;
+
+  pStore->fd = open(pStore->fname, O_RDWR);
+  if (pStore->fd < 0) {
+    uError("failed to open file %s since %s", pStore->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+
+  if (access(pStore->fsnap, F_OK) == 0) {
+    uTrace("file %s exists, try to recover the KV store", pStore->fsnap);
+    pStore->sfd = open(pStore->fsnap, O_RDONLY);
+    if (pStore->sfd < 0) {
+      uError("failed to open file %s since %s", pStore->fsnap, strerror(errno));
+      terrno = TAOS_SYSTEM_ERROR(errno);
+      goto _err;
+    }
+
+    // TODO: rewind the file
+
+    close(pStore->sfd);
+    pStore->sfd = -1;
+    remove(pStore->fsnap);
+  }
+
+  // TODO: Recover from the file
+
+  return pStore;
+
+_err:
+  if (pStore->fd > 0) {
+    close(pStore->fd);
+    pStore->fd = -1;
+  }
+  if (pStore->sfd > 0) {
+    close(pStore->sfd);
+    pStore->sfd = -1;
+  }
+  tdFreeKVStore(pStore);
+  return NULL;
+}
+
+int tdKVStoreStartCommit(SKVStore *pStore) {
+  pStore->fd = open(pStore->fname, O_RDWR);
+  if (pStore->fd < 0) {
+    uError("failed to open file %s since %s", pStore->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+
+  pStore->sfd = open(pStore->fsnap, O_WRONLY | O_CREAT, 0755);
+  if (pStore->sfd < 0) {
+    uError("failed to open file %s since %s", pStore->fsnap, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+
+  if (tsendfile(pStore->sfd, pStore->fd, NULL, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
+    uError("failed to send file %d bytes since %s", TD_KVSTORE_HEADER_SIZE, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+
+  if (fsync(pStore->sfd) < 0) {
+    uError("failed to fsync file %s since %s", pStore->fsnap, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+
+  if (close(pStore->sfd) < 0) {
+    uError("failed to close file %s since %s", pStore->fsnap, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+  pStore->sfd = -1;
+
+  return 0;
+
+_err:
+  if (pStore->sfd > 0) {
+    close(pStore->sfd);
+    pStore->sfd = -1;
+    remove(pStore->fsnap);
+  }
+  if (pStore->fd > 0) {
+    close(pStore->fd);
+    pStore->fd = -1;
+  }
+  return -1;
+}
+
+int tdKVStoreEndCommit(SKVStore *pStore) {
+  ASSERT(pStore->fd > 0);
+
+  if (fsync(pStore->fd) < 0) {
+    uError("failed to fsync file %s since %s", pStore->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
+  if (close(pStore->fd) < 0) {
+    uError("failed to close file %s since %s", pStore->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
+  remove(pStore->fsnap);
+  return 0;
+}
+
+static int tdUpdateKVStoreHeader(int fd, char *fname, SStoreInfo *pInfo) {
+  char buf[TD_KVSTORE_HEADER_SIZE] = "\0";
+
+  if (lseek(fd, 0, SEEK_SET) < 0) {
+    uError("failed to lseek file %s since %s", fname, strerror(errno));
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  tdEncodeStoreInfo(buf, pInfo);
+  taosCalcChecksumAppend(0, (uint8_t *)buf, TD_KVSTORE_HEADER_SIZE);
+  if (twrite(fd, buf, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
+    uError("failed to write file %s %d bytes since %s", fname, TD_KVSTORE_HEADER_SIZE, strerror(errno));
+    return TAOS_SYSTEM_ERROR(errno);
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int tdInitKVStoreHeader(int fd, char *fname) {
+  SStoreInfo info = {TD_KVSTORE_HEADER_SIZE, 0, 0, 0};
+
+  return tdUpdateKVStoreHeader(fd, fname, &info);
+}
+
+static void *tdEncodeStoreInfo(void *buf, SStoreInfo *pInfo) {
+  buf = taosEncodeVariantI64(buf, pInfo->size);
+  buf = taosEncodeVariantI64(buf, pInfo->tombSize);
+  buf = taosEncodeVariantI64(buf, pInfo->nRecords);
+  buf = taosEncodeVariantI64(buf, pInfo->nDels);
+
+  return buf;
+}
+
+// static void *tdDecodeStoreInfo(void *buf, SStoreInfo *pInfo) {
+//   buf = taosDecodeVariantI64(buf, &(pInfo->size));
+//   buf = taosDecodeVariantI64(buf, &(pInfo->tombSize));
+//   buf = taosDecodeVariantI64(buf, &(pInfo->nRecords));
+//   buf = taosDecodeVariantI64(buf, &(pInfo->nDels));
+
+//   return buf;
+// }
+
+static SKVStore *tdNewKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void *appH) {
+  SKVStore *pStore = (SKVStore *)malloc(sizeof(SKVStore));
+  if (pStore == NULL) goto _err;
+
+  pStore->fname = strdup(fname);
+  if (pStore->map == NULL) goto _err;
+
+  pStore->fsnap = tdGetKVStoreSnapshotFname(fname);
+  if (pStore->fsnap == NULL) goto _err;
+
+  pStore->fnew = tdGetKVStoreNewFname(fname);
+  if (pStore->fnew == NULL) goto _err;
+
+  pStore->fd = -1;
+  pStore->sfd = -1;
+  pStore->nfd = -1;
+  pStore->iFunc = iFunc;
+  pStore->aFunc = aFunc;
+  pStore->appH = appH;
+  pStore->map = taosHashInit(4096, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), false);
+  if (pStore->map == NULL) {
+    terrno = TSDB_CODE_SERV_OUT_OF_MEMORY;
+    goto _err;
+  }
+
+  return pStore;
+
+_err:
+  terrno = TSDB_CODE_SERV_OUT_OF_MEMORY;
+  tdFreeKVStore(pStore);
+  return NULL;
+}
+
+static void tdFreeKVStore(SKVStore *pStore) {
+  if (pStore) {
+    tfree(pStore->fname);
+    tfree(pStore->fsnap);
+    tfree(pStore->fnew);
+    taosHashCleanup(pStore->map);
+    free(pStore);
+  }
+}
+
+static char *tdGetKVStoreSnapshotFname(char *fdata) {
+  size_t size = strlen(fdata) + strlen(TD_KVSTORE_SNAP_SUFFIX) + 1;
+  char * fname = malloc(size);
+  if (fname == NULL) {
+    terrno = TSDB_CODE_SERV_OUT_OF_MEMORY;
+    return NULL;
+  }
+  sprintf(fname, "%s%s", fdata, TD_KVSTORE_SNAP_SUFFIX);
+  return fname;
+}
+
+static char *tdGetKVStoreNewFname(char *fdata) {
+  size_t size = strlen(fdata) + strlen(TD_KVSTORE_NEW_SUFFIX) + 1;
+  char * fname = malloc(size);
+  if (fname == NULL) {
+    terrno = TSDB_CODE_SERV_OUT_OF_MEMORY;
+    return NULL;
+  }
+  sprintf(fname, "%s%s", fdata, TD_KVSTORE_NEW_SUFFIX);
+  return fname;
+}
\ No newline at end of file