Import SQLite 3.8.7.4.

third_party/sqlite/src/src/pcache.h

Index: third_party/sqlite/src/src/pcache.h
diff --git a/third_party/sqlite/src/src/pcache.h b/third_party/sqlite/src/src/pcache.h
index 33735d2cbb2dc159ca988e91f90b8658f91e5394..dd9bfc7451c308d3e2ced6f0aeb11b8633d196be 100644
--- a/third_party/sqlite/src/src/pcache.h
+++ b/third_party/sqlite/src/src/pcache.h
@@ -23,11 +23,12 @@ typedef struct PCache PCache;
 ** structure.
 */
 struct PgHdr {
-  void *pData;                   /* Content of this page */
+  sqlite3_pcache_page *pPage;    /* Pcache object page handle */
+  void *pData;                   /* Page data */
   void *pExtra;                  /* Extra content */
   PgHdr *pDirty;                 /* Transient list of dirty pages */
-  Pgno pgno;                     /* Page number for this page */
   Pager *pPager;                 /* The pager this page is part of */
+  Pgno pgno;                     /* Page number for this page */
 #ifdef SQLITE_CHECK_PAGES
   u32 pageHash;                  /* Hash of page content */
 #endif
@@ -52,6 +53,8 @@ struct PgHdr {
 #define PGHDR_REUSE_UNLIKELY    0x010  /* A hint that reuse is unlikely */
 #define PGHDR_DONT_WRITE        0x020  /* Do not write content to disk */
 
+#define PGHDR_MMAP              0x040  /* This is an mmap page object */
+
 /* Initialize and shutdown the page cache subsystem */
 int sqlite3PcacheInitialize(void);
 void sqlite3PcacheShutdown(void);
@@ -65,7 +68,7 @@ void sqlite3PCacheBufferSetup(void *, int sz, int n);
 ** Under memory stress, invoke xStress to try to make pages clean.
 ** Only clean and unpinned pages can be reclaimed.
 */
-void sqlite3PcacheOpen(
+int sqlite3PcacheOpen(
   int szPage,                    /* Size of every page */
   int szExtra,                   /* Extra space associated with each page */
   int bPurgeable,                /* True if pages are on backing store */
@@ -75,7 +78,7 @@ void sqlite3PcacheOpen(
 );
 
 /* Modify the page-size after the cache has been created. */
-void sqlite3PcacheSetPageSize(PCache *, int);
+int sqlite3PcacheSetPageSize(PCache *, int);
 
 /* Return the size in bytes of a PCache object.  Used to preallocate
 ** storage space.
@@ -85,7 +88,9 @@ int sqlite3PcacheSize(void);
 /* One release per successful fetch.  Page is pinned until released.
 ** Reference counted. 
 */
-int sqlite3PcacheFetch(PCache*, Pgno, int createFlag, PgHdr**);
+sqlite3_pcache_page *sqlite3PcacheFetch(PCache*, Pgno, int createFlag);
+int sqlite3PcacheFetchStress(PCache*, Pgno, sqlite3_pcache_page**);
+PgHdr *sqlite3PcacheFetchFinish(PCache*, Pgno, sqlite3_pcache_page *pPage);
 void sqlite3PcacheRelease(PgHdr*);
 
 void sqlite3PcacheDrop(PgHdr*);         /* Remove page from cache */
@@ -141,6 +146,9 @@ void sqlite3PcacheSetCachesize(PCache *, int);
 int sqlite3PcacheGetCachesize(PCache *);
 #endif
 
+/* Free up as much memory as possible from the page cache */
+void sqlite3PcacheShrink(PCache*);
+
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
 /* Try to return memory used by the pcache module to the main memory heap */
 int sqlite3PcacheReleaseMemory(int);