[sql] Import reference version of SQLite 3.17..

third_party/sqlite/sqlite-src-3170000/src/test_wsd.c

+/*
+** 2008 September 1
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** The code in this file contains sample implementations of the 
+** sqlite3_wsd_init() and sqlite3_wsd_find() functions required if the
+** SQLITE_OMIT_WSD symbol is defined at build time.
+*/
+
+#if defined(SQLITE_OMIT_WSD) && defined(SQLITE_TEST)
+
+#include "sqliteInt.h"
+
+#define PLS_HASHSIZE 43
+
+typedef struct ProcessLocalStorage ProcessLocalStorage;
+typedef struct ProcessLocalVar ProcessLocalVar;
+
+struct ProcessLocalStorage {
+  ProcessLocalVar *aData[PLS_HASHSIZE];
+  int nFree;
+  u8 *pFree;
+};
+
+struct ProcessLocalVar {
+  void *pKey;
+  ProcessLocalVar *pNext;
+};
+
+static ProcessLocalStorage *pGlobal = 0;
+
+int sqlite3_wsd_init(int N, int J){
+  if( !pGlobal ){
+    int nMalloc = N + sizeof(ProcessLocalStorage) + J*sizeof(ProcessLocalVar);
+    pGlobal = (ProcessLocalStorage *)malloc(nMalloc);
+    if( pGlobal ){
+      memset(pGlobal, 0, sizeof(ProcessLocalStorage));
+      pGlobal->nFree = nMalloc - sizeof(ProcessLocalStorage);
+      pGlobal->pFree = (u8 *)&pGlobal[1];
+    }
+  }
+
+  return pGlobal ? SQLITE_OK : SQLITE_NOMEM;
+}
+
+void *sqlite3_wsd_find(void *K, int L){
+  int i;
+  int iHash = 0;
+  ProcessLocalVar *pVar;
+
+  /* Calculate a hash of K */
+  for(i=0; i<sizeof(void*); i++){
+    iHash = (iHash<<3) + ((unsigned char *)&K)[i];
+  }
+  iHash = iHash%PLS_HASHSIZE;
+
+  /* Search the hash table for K. */
+  for(pVar=pGlobal->aData[iHash]; pVar && pVar->pKey!=K; pVar=pVar->pNext);
+
+  /* If no entry for K was found, create and populate a new one. */
+  if( !pVar ){
+    int nByte = ROUND8(sizeof(ProcessLocalVar) + L);
+    assert( pGlobal->nFree>=nByte );
+    pVar = (ProcessLocalVar *)pGlobal->pFree;
+    pVar->pKey = K;
+    pVar->pNext = pGlobal->aData[iHash];
+    pGlobal->aData[iHash] = pVar;
+    pGlobal->nFree -= nByte;
+    pGlobal->pFree += nByte;
+    memcpy(&pVar[1], K, L);
+  }
+
+  return (void *)&pVar[1];
+}
+
+#endif