From 586381f8db3497c24c11f96234f1879b34e74bc7 Mon Sep 17 00:00:00 2001
From: "mpcomplete@google.com"
 <mpcomplete@google.com@0039d316-1c4b-4281-b951-d872f2087c98>
Date: Tue, 6 Jan 2009 22:39:41 +0000
Subject: Upgrade our sqlite to 3.6.1, with the local changes made by Gears. 
 I'm checking in the full sqlite tree to make upstream merges easier.  This
 means we'll have generated sources split out from the originals.

One important change this makes is that "BEGIN" now defaults to "BEGIN
IMMEDIATE" rather than "BEGIN DEFERRED".  This doesn't affect us because we
don't use unqualified BEGIN statements.

The full CL is too big for Rietveld.  I'm splitting it into 2.  This one is
reviewable.  The other CL is just a fresh drop of:
//depot/googleclient/gears/opensource/third_party/sqlite_google
Review URL: http://codereview.chromium.org/15067

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@7623 0039d316-1c4b-4281-b951-d872f2087c98
---
 third_party/sqlite/src/mem6.c | 496 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 496 insertions(+)
 create mode 100755 third_party/sqlite/src/mem6.c

(limited to 'third_party/sqlite/src/mem6.c')

diff --git a/third_party/sqlite/src/mem6.c b/third_party/sqlite/src/mem6.c
new file mode 100755
index 0000000..95723ad
--- /dev/null
+++ b/third_party/sqlite/src/mem6.c
@@ -0,0 +1,496 @@
+/*
+** 2008 July 24
+**
+** 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.
+**
+*************************************************************************
+**
+** This file contains an alternative memory allocation system for SQLite.
+** This system is implemented as a wrapper around the system provided
+** by the operating system - vanilla malloc(), realloc() and free().
+**
+** This system differentiates between requests for "small" allocations 
+** (by default those of 128 bytes or less) and "large" allocations (all
+** others). The 256 byte threshhold is configurable at runtime.
+**
+** All requests for large allocations are passed through to the 
+** default system.
+**
+** Requests for small allocations are met by allocating space within
+** one or more larger "chunks" of memory obtained from the default
+** memory allocation system. Chunks of memory are usually 64KB or 
+** larger. The algorithm used to manage space within each chunk is
+** the same as that used by mem5.c. 
+**
+** This strategy is designed to prevent the default memory allocation
+** system (usually the system malloc) from suffering from heap 
+** fragmentation. On some systems, heap fragmentation can cause a 
+** significant real-time slowdown.
+**
+** $Id: mem6.c,v 1.7 2008/07/28 19:34:53 drh Exp $
+*/
+
+#ifdef SQLITE_ENABLE_MEMSYS6
+
+#include "sqliteInt.h"
+
+/*
+** Maximum size of any "small" allocation is ((1<<LOGMAX)*Mem6Chunk.nAtom).
+** Mem6Chunk.nAtom is always at least 8, so this is not a practical
+** limitation
+*/
+#define LOGMAX 30
+
+/*
+** Default value for the "small" allocation size threshold.
+*/
+#define SMALL_MALLOC_DEFAULT_THRESHOLD 256
+
+/*
+** Minimum size for a memory chunk.
+*/
+#define MIN_CHUNKSIZE (1<<16)
+
+#define LOG2_MINALLOC 4
+
+
+typedef struct Mem6Chunk Mem6Chunk;
+typedef struct Mem6Link Mem6Link;
+
+/*
+** A minimum allocation is an instance of the following structure.
+** Larger allocations are an array of these structures where the
+** size of the array is a power of 2.
+*/
+struct Mem6Link {
+  int next;       /* Index of next free chunk */
+  int prev;       /* Index of previous free chunk */
+};
+
+/*
+** Masks used for mem5.aCtrl[] elements.
+*/
+#define CTRL_LOGSIZE  0x1f    /* Log2 Size of this block relative to POW2_MIN */
+#define CTRL_FREE     0x20    /* True if not checked out */
+
+struct Mem6Chunk {
+  Mem6Chunk *pNext;
+
+  /*
+  ** Lists of free blocks of various sizes.
+  */
+  int aiFreelist[LOGMAX+1];
+
+  int nCheckedOut; /* Number of currently outstanding allocations */
+
+  /*
+  ** Space for tracking which blocks are checked out and the size
+  ** of each block. One byte per block.
+  */
+  u8 *aCtrl;
+
+  /*
+  ** Memory available for allocation
+  */
+  int nAtom;       /* Smallest possible allocation in bytes */
+  int nBlock;      /* Number of nAtom sized blocks in zPool */
+  u8 *zPool;       /* Pointer to memory chunk from which allocations are made */
+};
+
+#define MEM6LINK(idx) ((Mem6Link *)(&pChunk->zPool[(idx)*pChunk->nAtom]))
+
+struct Mem6Global {
+  int nMinAlloc;                  /* Minimum allowed allocation size */
+  int nThreshold;                 /* Allocs larger than this go to malloc() */
+  int nLogThreshold;              /* log2 of (nThreshold/nMinAlloc) */
+  sqlite3_mutex *mutex;
+  Mem6Chunk *pChunk;              /* Singly linked list of all memory chunks */
+} mem6;
+
+/*
+** Unlink the chunk at pChunk->aPool[i] from list it is currently
+** on.  It should be found on pChunk->aiFreelist[iLogsize].
+*/
+static void memsys6Unlink(Mem6Chunk *pChunk, int i, int iLogsize){
+  int next, prev;
+  assert( i>=0 && i<pChunk->nBlock );
+  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
+  assert( (pChunk->aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
+
+  next = MEM6LINK(i)->next;
+  prev = MEM6LINK(i)->prev;
+  if( prev<0 ){
+    pChunk->aiFreelist[iLogsize] = next;
+  }else{
+    MEM6LINK(prev)->next = next;
+  }
+  if( next>=0 ){
+    MEM6LINK(next)->prev = prev;
+  }
+}
+
+/*
+** Link the chunk at mem5.aPool[i] so that is on the iLogsize
+** free list.
+*/
+static void memsys6Link(Mem6Chunk *pChunk, int i, int iLogsize){
+  int x;
+  assert( i>=0 && i<pChunk->nBlock );
+  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
+  assert( (pChunk->aCtrl[i] & CTRL_LOGSIZE)==iLogsize );
+
+  x = MEM6LINK(i)->next = pChunk->aiFreelist[iLogsize];
+  MEM6LINK(i)->prev = -1;
+  if( x>=0 ){
+    assert( x<pChunk->nBlock );
+    MEM6LINK(x)->prev = i;
+  }
+  pChunk->aiFreelist[iLogsize] = i;
+}
+
+
+/*
+** Find the first entry on the freelist iLogsize.  Unlink that
+** entry and return its index. 
+*/
+static int memsys6UnlinkFirst(Mem6Chunk *pChunk, int iLogsize){
+  int i;
+  int iFirst;
+
+  assert( iLogsize>=0 && iLogsize<=mem6.nLogThreshold );
+  i = iFirst = pChunk->aiFreelist[iLogsize];
+  assert( iFirst>=0 );
+  memsys6Unlink(pChunk, iFirst, iLogsize);
+  return iFirst;
+}
+
+static int roundupLog2(int n){
+  static const char LogTable256[256] = {
+    0,                                                    /* 1 */
+    1,                                                    /* 2 */
+    2, 2,                                                 /* 3..4 */
+    3, 3, 3, 3,                                           /* 5..8 */
+    4, 4, 4, 4, 4, 4, 4, 4,                               /* 9..16 */
+    5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,       /* 17..32 */
+    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,       /* 33..64 */
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,       /* 65..128 */
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,       /* 129..256 */
+  };
+
+  assert(n<=(1<<16) && n>0);
+  if( n<=256 ) return LogTable256[n-1];
+  return LogTable256[(n>>8) - ((n&0xFF)?0:1)] + 8;
+}
+
+/*
+** Allocate and return a block of (pChunk->nAtom << iLogsize) bytes from chunk
+** pChunk. If the allocation request cannot be satisfied, return 0.
+*/
+static void *chunkMalloc(Mem6Chunk *pChunk, int iLogsize){
+  int i;           /* Index of a mem5.aPool[] slot */
+  int iBin;        /* Index into mem5.aiFreelist[] */
+
+  /* Make sure mem5.aiFreelist[iLogsize] contains at least one free
+  ** block.  If not, then split a block of the next larger power of
+  ** two in order to create a new free block of size iLogsize.
+  */
+  for(iBin=iLogsize; pChunk->aiFreelist[iBin]<0 && iBin<=mem6.nLogThreshold; iBin++){}
+  if( iBin>mem6.nLogThreshold ) return 0;
+  i = memsys6UnlinkFirst(pChunk, iBin);
+  while( iBin>iLogsize ){
+    int newSize;
+    iBin--;
+    newSize = 1 << iBin;
+    pChunk->aCtrl[i+newSize] = CTRL_FREE | iBin;
+    memsys6Link(pChunk, i+newSize, iBin);
+  }
+  pChunk->aCtrl[i] = iLogsize;
+
+  /* Return a pointer to the allocated memory. */
+  pChunk->nCheckedOut++;
+  return (void*)&pChunk->zPool[i*pChunk->nAtom];
+}
+
+/*
+** Free the allocation pointed to by p, which is guaranteed to be non-zero
+** and a part of chunk object pChunk.
+*/
+static void chunkFree(Mem6Chunk *pChunk, void *pOld){
+  u32 size, iLogsize;
+  int iBlock;             
+
+  /* Set iBlock to the index of the block pointed to by pOld in 
+  ** the array of pChunk->nAtom byte blocks pointed to by pChunk->zPool.
+  */
+  iBlock = ((u8 *)pOld-pChunk->zPool)/pChunk->nAtom;
+
+  /* Check that the pointer pOld points to a valid, non-free block. */
+  assert( iBlock>=0 && iBlock<pChunk->nBlock );
+  assert( ((u8 *)pOld-pChunk->zPool)%pChunk->nAtom==0 );
+  assert( (pChunk->aCtrl[iBlock] & CTRL_FREE)==0 );
+
+  iLogsize = pChunk->aCtrl[iBlock] & CTRL_LOGSIZE;
+  size = 1<<iLogsize;
+  assert( iBlock+size-1<pChunk->nBlock );
+
+  pChunk->aCtrl[iBlock] |= CTRL_FREE;
+  pChunk->aCtrl[iBlock+size-1] |= CTRL_FREE;
+
+  pChunk->aCtrl[iBlock] = CTRL_FREE | iLogsize;
+  while( iLogsize<mem6.nLogThreshold ){
+    int iBuddy;
+    if( (iBlock>>iLogsize) & 1 ){
+      iBuddy = iBlock - size;
+    }else{
+      iBuddy = iBlock + size;
+    }
+    assert( iBuddy>=0 );
+    if( (iBuddy+(1<<iLogsize))>pChunk->nBlock ) break;
+    if( pChunk->aCtrl[iBuddy]!=(CTRL_FREE | iLogsize) ) break;
+    memsys6Unlink(pChunk, iBuddy, iLogsize);
+    iLogsize++;
+    if( iBuddy<iBlock ){
+      pChunk->aCtrl[iBuddy] = CTRL_FREE | iLogsize;
+      pChunk->aCtrl[iBlock] = 0;
+      iBlock = iBuddy;
+    }else{
+      pChunk->aCtrl[iBlock] = CTRL_FREE | iLogsize;
+      pChunk->aCtrl[iBuddy] = 0;
+    }
+    size *= 2;
+  }
+  pChunk->nCheckedOut--;
+  memsys6Link(pChunk, iBlock, iLogsize);
+}
+
+/*
+** Return the actual size of the block pointed to by p, which is guaranteed
+** to have been allocated from chunk pChunk.
+*/
+static int chunkSize(Mem6Chunk *pChunk, void *p){
+  int iSize = 0;
+  if( p ){
+    int i = ((u8 *)p-pChunk->zPool)/pChunk->nAtom;
+    assert( i>=0 && i<pChunk->nBlock );
+    iSize = pChunk->nAtom * (1 << (pChunk->aCtrl[i]&CTRL_LOGSIZE));
+  }
+  return iSize;
+}
+
+/*
+** Return true if there are currently no outstanding allocations.
+*/
+static int chunkIsEmpty(Mem6Chunk *pChunk){
+  return (pChunk->nCheckedOut==0);
+}
+
+/*
+** Initialize the buffer zChunk, which is nChunk bytes in size, as
+** an Mem6Chunk object. Return a copy of the zChunk pointer.
+*/
+static Mem6Chunk *chunkInit(u8 *zChunk, int nChunk, int nMinAlloc){
+  int ii;
+  int iOffset;
+  Mem6Chunk *pChunk = (Mem6Chunk *)zChunk;
+
+  assert( nChunk>sizeof(Mem6Chunk) );
+  assert( nMinAlloc>sizeof(Mem6Link) );
+
+  memset(pChunk, 0, sizeof(Mem6Chunk));
+  pChunk->nAtom = nMinAlloc;
+  pChunk->nBlock = ((nChunk-sizeof(Mem6Chunk)) / (pChunk->nAtom+sizeof(u8)));
+
+  pChunk->zPool = (u8 *)&pChunk[1];
+  pChunk->aCtrl = &pChunk->zPool[pChunk->nBlock*pChunk->nAtom];
+
+  for(ii=0; ii<=mem6.nLogThreshold; ii++){
+    pChunk->aiFreelist[ii] = -1;
+  }
+
+  iOffset = 0;
+  for(ii=mem6.nLogThreshold; ii>=0; ii--){
+    int nAlloc = (1<<ii);
+    while( (iOffset+nAlloc)<=pChunk->nBlock ){
+      pChunk->aCtrl[iOffset] = ii | CTRL_FREE;
+      memsys6Link(pChunk, iOffset, ii);
+      iOffset += nAlloc;
+    }
+  }
+
+  return pChunk;
+}
+
+
+static void mem6Enter(void){
+  sqlite3_mutex_enter(mem6.mutex);
+}
+
+static void mem6Leave(void){
+  sqlite3_mutex_leave(mem6.mutex);
+}
+
+/*
+** Based on the number and size of the currently allocated chunks, return
+** the size of the next chunk to allocate, in bytes.
+*/
+static int nextChunkSize(void){
+  int iTotal = MIN_CHUNKSIZE;
+  Mem6Chunk *p;
+  for(p=mem6.pChunk; p; p=p->pNext){
+    iTotal = iTotal*2;
+  }
+  return iTotal;
+}
+
+static void freeChunk(Mem6Chunk *pChunk){
+  Mem6Chunk **pp = &mem6.pChunk;
+  for( pp=&mem6.pChunk; *pp!=pChunk; pp = &(*pp)->pNext );
+  *pp = (*pp)->pNext;
+  free(pChunk);
+}
+
+static void *memsys6Malloc(int nByte){
+  Mem6Chunk *pChunk;
+  void *p = 0;
+  int nTotal = nByte+8;
+  int iOffset = 0;
+
+  if( nTotal>mem6.nThreshold ){
+    p = malloc(nTotal);
+  }else{
+    int iLogsize = 0;
+    if( nTotal>(1<<LOG2_MINALLOC) ){
+      iLogsize = roundupLog2(nTotal) - LOG2_MINALLOC;
+    }
+    mem6Enter();
+    for(pChunk=mem6.pChunk; pChunk; pChunk=pChunk->pNext){
+      p = chunkMalloc(pChunk, iLogsize);
+      if( p ){
+        break;
+      }
+    }
+    if( !p ){
+      int iSize = nextChunkSize();
+      p = malloc(iSize);
+      if( p ){
+        pChunk = chunkInit((u8 *)p, iSize, mem6.nMinAlloc);
+        pChunk->pNext = mem6.pChunk;
+        mem6.pChunk = pChunk;
+        p = chunkMalloc(pChunk, iLogsize);
+        assert(p);
+      }
+    }
+    iOffset = ((u8*)p - (u8*)pChunk);
+    mem6Leave();
+  }
+
+  if( !p ){
+    return 0;
+  }
+  ((u32 *)p)[0] = iOffset;
+  ((u32 *)p)[1] = nByte;
+  return &((u32 *)p)[2];
+}
+
+static int memsys6Size(void *pPrior){
+  if( pPrior==0 ) return 0;
+  return ((u32*)pPrior)[-1];
+}
+
+static void memsys6Free(void *pPrior){
+  int iSlot;
+  void *p = &((u32 *)pPrior)[-2];
+  iSlot = ((u32 *)p)[0];
+  if( iSlot ){
+    Mem6Chunk *pChunk;
+    mem6Enter();
+    pChunk = (Mem6Chunk *)(&((u8 *)p)[-1 * iSlot]);
+    chunkFree(pChunk, p);
+    if( chunkIsEmpty(pChunk) ){
+      freeChunk(pChunk);
+    }
+    mem6Leave();
+  }else{
+    free(p);
+  }
+}
+
+static void *memsys6Realloc(void *p, int nByte){
+  void *p2;
+
+  if( p && nByte<=memsys6Size(p) ){
+    p2 = p;
+  }else{
+    p2 = memsys6Malloc(nByte);
+    if( p && p2 ){
+      memcpy(p2, p, memsys6Size(p));
+      memsys6Free(p);
+    }
+  }
+
+  return p2;
+}
+
+static int memsys6Roundup(int n){
+  if( n>mem6.nThreshold ){
+    return n;
+  }else{
+    return (1<<roundupLog2(n));
+  }
+}
+
+static int memsys6Init(void *pCtx){
+  u8 bMemstat = sqlite3Config.bMemstat;
+  mem6.nMinAlloc = (1 << LOG2_MINALLOC);
+  mem6.pChunk = 0;
+  mem6.nThreshold = sqlite3Config.nSmall;
+  if( mem6.nThreshold<=0 ){
+    mem6.nThreshold = SMALL_MALLOC_DEFAULT_THRESHOLD;
+  }
+  mem6.nLogThreshold = roundupLog2(mem6.nThreshold) - LOG2_MINALLOC;
+  if( !bMemstat ){
+    mem6.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
+  }
+  return SQLITE_OK;
+}
+
+static void memsys6Shutdown(void *pCtx){
+  memset(&mem6, 0, sizeof(mem6));
+}
+
+/*
+** This routine is the only routine in this file with external 
+** linkage. It returns a pointer to a static sqlite3_mem_methods
+** struct populated with the memsys6 methods.
+*/
+const sqlite3_mem_methods *sqlite3MemGetMemsys6(void){
+  static const sqlite3_mem_methods memsys6Methods = {
+     memsys6Malloc,
+     memsys6Free,
+     memsys6Realloc,
+     memsys6Size,
+     memsys6Roundup,
+     memsys6Init,
+     memsys6Shutdown,
+     0
+  };
+  return &memsys6Methods;
+}
+
+#endif
-- 
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