From a466372179f897abb4e3bbe3546a4c06e2795582 Mon Sep 17 00:00:00 2001
From: Hongze Cheng <hzcheng@taosdata.com>
Date: Thu, 31 Mar 2022 02:10:26 +0000
Subject: [PATCH] more TDB

---
 source/libs/tdb/src/db/tdbEnv.c    | 71 ++++++++++++++++++++++++++----
 source/libs/tdb/src/inc/tdbEnv.h   | 13 +++---
 source/libs/tdb/src/inc/tdbPager.h |  2 +
 source/libs/tdb/src/inc/tdbUtil.h  |  5 +++
 4 files changed, 75 insertions(+), 16 deletions(-)

diff --git a/source/libs/tdb/src/db/tdbEnv.c b/source/libs/tdb/src/db/tdbEnv.c
index a981e8c99e..6e74aefc62 100644
--- a/source/libs/tdb/src/db/tdbEnv.c
+++ b/source/libs/tdb/src/db/tdbEnv.c
@@ -54,13 +54,13 @@ int tdbEnvOpen(const char *rootDir, int pageSize, int cacheSize, TENV **ppEnv) {
     return -1;
   }
 
-  pEnv->nHash = 8;
-  tsize = sizeof(SPager *) * pEnv->nHash;
-  pEnv->pagerHash = TDB_REALLOC(pEnv->pagerHash, tsize);
-  if (pEnv->pagerHash == NULL) {
+  pEnv->nPgrHash = 8;
+  tsize = sizeof(SPager *) * pEnv->nPgrHash;
+  pEnv->pgrHash = TDB_REALLOC(pEnv->pgrHash, tsize);
+  if (pEnv->pgrHash == NULL) {
     return -1;
   }
-  memset(pEnv->pagerHash, 0, tsize);
+  memset(pEnv->pgrHash, 0, tsize);
 
   mkdir(rootDir, 0755);
 
@@ -81,7 +81,7 @@ int tdbBegin(TENV *pEnv) {
 int tdbCommit(TENV *pEnv) {
   SPager *pPager;
 
-  pPager = pEnv->pagerList;
+  pPager = pEnv->pgrList;
   while (pPager) {
     tdbPagerCommit(pPager);
   }
@@ -95,10 +95,63 @@ int tdbRollback(TENV *pEnv) {
 }
 
 SPager *tdbEnvGetPager(TENV *pEnv, const char *fname) {
-  // TODO
-  return NULL;
+  int      hash;
+  SPager **ppPager;
+
+  hash = tdbCstringHash(fname);
+  ppPager = &pEnv->pgrHash[hash % pEnv->nPgrHash];
+  for (; *ppPager && (strcmp(fname, (*ppPager)->dbFileName) != 0); ppPager = &((*ppPager)->pHashNext)) {
+  }
+
+  return *ppPager;
 }
 
-static void tdbEnvAddPager(TENV *pEnv, SPager *pPager) {
+void tdbEnvAddPager(TENV *pEnv, SPager *pPager) {
+  int      hash;
+  SPager **ppPager;
 
+  // rehash if neccessary
+  if (pEnv->nPager + 1 > pEnv->nPgrHash) {
+    // TODO
+  }
+
+  // add to list
+  pPager->pNext = pEnv->pgrList;
+  pEnv->pgrList = pPager;
+
+  // add to hash
+  hash = tdbCstringHash(pPager->dbFileName);
+  ppPager = &pEnv->pgrHash[hash % pEnv->nPgrHash];
+  pPager->pHashNext = *ppPager;
+  *ppPager = pPager;
+
+  // increase the counter
+  pEnv->nPager++;
+}
+
+void tdbEnvRemovePager(TENV *pEnv, SPager *pPager) {
+  int      hash;
+  SPager **ppPager;
+
+  // remove from the list
+  for (ppPager = &pEnv->pgrList; *ppPager && (*ppPager != pPager); ppPager = &((*ppPager)->pNext)) {
+  }
+  ASSERT(*ppPager == pPager);
+  *ppPager = pPager->pNext;
+
+  // remove from hash
+  hash = tdbCstringHash(pPager->dbFileName);
+  ppPager = &pEnv->pgrHash[hash % pEnv->nPgrHash];
+  for (; *ppPager && *ppPager != pPager; ppPager = &((*ppPager)->pHashNext)) {
+  }
+  ASSERT(*ppPager == pPager);
+  *ppPager = pPager->pNext;
+
+  // decrease the counter
+  pEnv->nPager--;
+
+  // rehash if necessary
+  if (pEnv->nPgrHash > 8 && pEnv->nPager < pEnv->nPgrHash / 2) {
+    // TODO
+  }
 }
\ No newline at end of file
diff --git a/source/libs/tdb/src/inc/tdbEnv.h b/source/libs/tdb/src/inc/tdbEnv.h
index 3eb3ebb328..e10c5d54e0 100644
--- a/source/libs/tdb/src/inc/tdbEnv.h
+++ b/source/libs/tdb/src/inc/tdbEnv.h
@@ -20,18 +20,15 @@
 extern "C" {
 #endif
 
-#define TDB_PAGER_ENV_FIELDS \
-  SPager *pNext;             \
-  SPager *pHashNext;
-
 typedef struct STEnv {
   char    *rootDir;
   char    *jfname;
   int      jfd;
   SPCache *pCache;
-  SPager  *pagerList;
-  int      nHash;
-  SPager **pagerHash;
+  SPager  *pgrList;
+  int      nPager;
+  int      nPgrHash;
+  SPager **pgrHash;
 } TENV;
 
 int tdbEnvOpen(const char *rootDir, int pageSize, int cacheSize, TENV **ppEnv);
@@ -40,6 +37,8 @@ int tdbBegin(TENV *pEnv);
 int tdbCommit(TENV *pEnv);
 int tdbRollback(TENV *pEnv);
 
+void    tdbEnvAddPager(TENV *pEnv, SPager *pPager);
+void    tdbEnvRemovePager(TENV *pEnv, SPager *pPager);
 SPager *tdbEnvGetPager(TENV *pEnv, const char *fname);
 
 #ifdef __cplusplus
diff --git a/source/libs/tdb/src/inc/tdbPager.h b/source/libs/tdb/src/inc/tdbPager.h
index 7ae86eb3ac..81b6074431 100644
--- a/source/libs/tdb/src/inc/tdbPager.h
+++ b/source/libs/tdb/src/inc/tdbPager.h
@@ -32,6 +32,8 @@ struct SPager {
   SPgno    dbOrigSize;
   SPage   *pDirty;
   u8       inTran;
+  SPager  *pNext;      // used by TENV
+  SPager  *pHashNext;  // used by TENV
 };
 
 int  tdbPagerOpen(SPCache *pCache, const char *fileName, SPager **ppPager);
diff --git a/source/libs/tdb/src/inc/tdbUtil.h b/source/libs/tdb/src/inc/tdbUtil.h
index c06d9d18c9..a4cb09ea94 100644
--- a/source/libs/tdb/src/inc/tdbUtil.h
+++ b/source/libs/tdb/src/inc/tdbUtil.h
@@ -101,6 +101,11 @@ static inline int tdbGetVarInt(const u8 *p, int *v) {
   return n;
 }
 
+static inline int tdbCstringHash(const char *s) {
+  // TODO
+  return 0;
+}
+
 #ifdef __cplusplus
 }
 #endif
-- 
GitLab