Import the LSM code from SQLite4 for use in an experimental virtual table.

NB: This is a speculative experiment and could easily result in a dead-end
branch.

FossilOrigin-Name: 3d930501a2acb7f20932cfeb4e3fe308b4569cd6

ext/lsm1/lsm_mem.c

@@ -0,0 +1,104 @@
+/*
+** 2011-08-18
+**
+** 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.
+**
+*************************************************************************
+**
+** Helper routines for memory allocation.
+*/
+#include "lsmInt.h"
+
+/*
+** The following routines are called internally by LSM sub-routines. In
+** this case a valid environment pointer must be supplied.
+*/
+void *lsmMalloc(lsm_env *pEnv, size_t N){
+  assert( pEnv );
+  return pEnv->xMalloc(pEnv, N);
+}
+void lsmFree(lsm_env *pEnv, void *p){
+  assert( pEnv );
+  pEnv->xFree(pEnv, p);
+}
+void *lsmRealloc(lsm_env *pEnv, void *p, size_t N){
+  assert( pEnv );
+  return pEnv->xRealloc(pEnv, p, N);
+}
+
+/*
+** Core memory allocation routines for LSM.
+*/
+void *lsm_malloc(lsm_env *pEnv, size_t N){
+  return lsmMalloc(pEnv ? pEnv : lsm_default_env(), N);
+}
+void lsm_free(lsm_env *pEnv, void *p){
+  lsmFree(pEnv ? pEnv : lsm_default_env(), p);
+}
+void *lsm_realloc(lsm_env *pEnv, void *p, size_t N){
+  return lsmRealloc(pEnv ? pEnv : lsm_default_env(), p, N);
+}
+
+void *lsmMallocZero(lsm_env *pEnv, size_t N){
+  void *pRet;
+  assert( pEnv );
+  pRet = lsmMalloc(pEnv, N);
+  if( pRet ) memset(pRet, 0, N);
+  return pRet;
+}
+
+void *lsmMallocRc(lsm_env *pEnv, size_t N, int *pRc){
+  void *pRet = 0;
+  if( *pRc==LSM_OK ){
+    pRet = lsmMalloc(pEnv, N);
+    if( pRet==0 ){
+      *pRc = LSM_NOMEM_BKPT;
+    }
+  }
+  return pRet;
+}
+
+void *lsmMallocZeroRc(lsm_env *pEnv, size_t N, int *pRc){
+  void *pRet = 0;
+  if( *pRc==LSM_OK ){
+    pRet = lsmMallocZero(pEnv, N);
+    if( pRet==0 ){
+      *pRc = LSM_NOMEM_BKPT;
+    }
+  }
+  return pRet;
+}
+
+void *lsmReallocOrFree(lsm_env *pEnv, void *p, size_t N){
+  void *pNew;
+  pNew = lsm_realloc(pEnv, p, N);
+  if( !pNew ) lsm_free(pEnv, p);
+  return pNew;
+}
+
+void *lsmReallocOrFreeRc(lsm_env *pEnv, void *p, size_t N, int *pRc){
+  void *pRet = 0;
+  if( *pRc ){
+    lsmFree(pEnv, p);
+  }else{
+    pRet = lsmReallocOrFree(pEnv, p, N);
+    if( !pRet ) *pRc = LSM_NOMEM_BKPT;
+  }
+  return pRet;
+}
+
+char *lsmMallocStrdup(lsm_env *pEnv, const char *zIn){
+  int nByte;
+  char *zRet;
+  nByte = strlen(zIn);
+  zRet = lsmMalloc(pEnv, nByte+1);
+  if( zRet ){
+    memcpy(zRet, zIn, nByte+1);
+  }
+  return zRet;
+}