more TDB

source/libs/tdb/src/db/pgcache.c

@@ -19,6 +19,7 @@ struct SPage {
   pgid_t      pgid;      // page id
   frame_id_t  frameid;   // frame id
   SPgListNode freeNode;  // for SPgCache.freeList
+  SPgListNode pghtNode;  // for pght
   uint8_t *   pData;     // real data
 };
 
@@ -36,6 +37,8 @@ struct SPgCache {
   } pght;  // page hash table
 };
 
+static void pgCachePinPage(SPage *pPage);
+
 int pgCacheCreate(SPgCache **ppPgCache, pgsize_t pgSize, int32_t npage) {
   SPgCache *pPgCache;
   SPage *   pPage;
@@ -123,13 +126,37 @@ int pgCacheClose(SPgCache *pPgCache) {
 }
 
 SPage *pgCacheFetch(SPgCache *pPgCache, pgid_t pgid) {
-  SPage *pPage;
+  SPage *  pPage;
+  SPgFile *pPgFile;
+  SPgList *pBucket;
+
+  // 1. Search the page hash table SPgCache.pght
+  pBucket = pPgCache->pght.buckets + ((0 /*TODO*/) % pPgCache->pght.nbucket);
+  pPage = TD_DLIST_HEAD(pBucket);
+  while (pPage && tdbCmprPgId(&(pPage->pgid), &pgid)) {
+    pPage = TD_DLIST_NODE_NEXT_WITH_FIELD(pPage, pghtNode);
+  }
+
+  if (pPage) {
+    // Page is found, pin the page (TODO) and return the page
+    pgCachePinPage(pPage);
+    return pPage;
+  }
+
+  // TODO
 
-  // 1. Check if the page is cached
   return NULL;
 }
 
 int pgCacheRelease(SPage *pPage) {
   // TODO
   return 0;
+}
+
+static void pgCachePinPage(SPage *pPage) {
+  // TODO
+}
+
+static void pgCacheUnpinPage(SPage *pPage) {
+  // TODO
 }

source/libs/tdb/src/inc/tdbInt.h

@@ -38,8 +38,28 @@ typedef struct {
   uint8_t fileid[TDB_FILE_ID_LEN];
   pgno_t  pgno;
 } pgid_t;
+
 #define TDB_IVLD_PGID (pgid_t){0, TDB_IVLD_PGNO};
 
+static FORCE_INLINE int tdbCmprPgId(const void *p1, const void *p2) {
+  pgid_t *pgid1 = (pgid_t *)p1;
+  pgid_t *pgid2 = (pgid_t *)p2;
+  int     rcode;
+
+  rcode = memcmp(pgid1->fileid, pgid2->fileid, TDB_FILE_ID_LEN);
+  if (rcode) {
+    return rcode;
+  } else {
+    if (pgid1->pgno > pgid2->pgno) {
+      return 1;
+    } else if (pgid1->pgno < pgid2->pgno) {
+      return -1;
+    } else {
+      return 0;
+    }
+  }
+}
+
 // framd_id_t
 typedef int32_t frame_id_t;
 
@@ -51,14 +71,14 @@ typedef int32_t pgsize_t;
 #define TDB_IS_PGSIZE_VLD(s) (((s) >= TDB_MIN_PGSIZE) && ((s) <= TDB_MAX_PGSIZE))
 
 // cache
-#define TDB_DEFAULT_CACHE_SIZE (256 * 1024) // 256K
+#define TDB_DEFAULT_CACHE_SIZE (256 * 1024)  // 256K
 
 // tdb_log
 #define tdbError(var)
 
+#include "btree.h"
 #include "pgcache.h"
 #include "pgfile.h"
-#include "btree.h"
 
 // tdb util
 int tdbGnrtFileID(const char *fname, uint8_t *fileid);