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Data Structures | Macros | Typedefs | Functions
ID List Management
LMDB Internals

Data Structures

struct  MDB_ID2
 

Macros

#define MDB_IDL_LOGN   16 /* DB_SIZE is 2^16, UM_SIZE is 2^17 */
 
#define MDB_IDL_DB_SIZE   (1<<MDB_IDL_LOGN)
 
#define MDB_IDL_UM_SIZE   (1<<(MDB_IDL_LOGN+1))
 
#define MDB_IDL_DB_MAX   (MDB_IDL_DB_SIZE-1)
 
#define MDB_IDL_UM_MAX   (MDB_IDL_UM_SIZE-1)
 
#define MDB_IDL_SIZEOF(ids)   (((ids)[0]+1) * sizeof(MDB_ID))
 
#define MDB_IDL_IS_ZERO(ids)   ( (ids)[0] == 0 )
 
#define MDB_IDL_CPY(dst, src)   (memcpy( dst, src, MDB_IDL_SIZEOF( src ) ))
 
#define MDB_IDL_FIRST(ids)   ( (ids)[1] )
 
#define MDB_IDL_LAST(ids)   ( (ids)[(ids)[0]] )
 
#define MDB_IDL_ALLOCLEN(ids)   ( (ids)[-1] )
 
#define mdb_midl_xappend(idl, id)
 
#define CMP(x, y)   ( (x) < (y) ? -1 : (x) > (y) )
 
#define SMALL   8
 
#define MIDL_SWAP(a, b)   { itmp=(a); (a)=(b); (b)=itmp; }
 

Typedefs

typedef size_t MDB_ID
 
typedef MDB_IDMDB_IDL
 
typedef MDB_ID2MDB_ID2L
 

Functions

unsigned mdb_midl_search (MDB_IDL ids, MDB_ID id)
 
MDB_IDL mdb_midl_alloc (int num)
 
void mdb_midl_free (MDB_IDL ids)
 
void mdb_midl_shrink (MDB_IDL *idp)
 
int mdb_midl_need (MDB_IDL *idp, unsigned num)
 
int mdb_midl_append (MDB_IDL *idp, MDB_ID id)
 
int mdb_midl_append_list (MDB_IDL *idp, MDB_IDL app)
 
int mdb_midl_append_range (MDB_IDL *idp, MDB_ID id, unsigned n)
 
void mdb_midl_xmerge (MDB_IDL idl, MDB_IDL merge)
 
void mdb_midl_sort (MDB_IDL ids)
 
unsigned mdb_mid2l_search (MDB_ID2L ids, MDB_ID id)
 
int mdb_mid2l_insert (MDB_ID2L ids, MDB_ID2 *id)
 
int mdb_mid2l_append (MDB_ID2L ids, MDB_ID2 *id)
 
static int mdb_midl_grow (MDB_IDL *idp, int num)
 

Detailed Description


Data Structure Documentation

struct MDB_ID2

An ID2 is an ID/pointer pair.

Data Fields

MDB_ID mid
 
void * mptr
 

Field Documentation

MDB_ID MDB_ID2::mid

The ID

void* MDB_ID2::mptr

The pointer

Macro Definition Documentation

#define MDB_IDL_ALLOCLEN (   ids)    ( (ids)[-1] )

Current max length of an mdb_midl_alloc()ed IDL

#define mdb_midl_xappend (   idl,
  id 
)
Value:
do { \
MDB_ID *xidl = (idl), xlen = ++(xidl[0]); \
xidl[xlen] = (id); \
} while (0)

Append ID to IDL. The IDL must be big enough.

Typedef Documentation

typedef size_t MDB_ID

A generic unsigned ID number. These were entryIDs in back-bdb. Preferably it should have the same size as a pointer.

typedef MDB_ID* MDB_IDL

An IDL is an ID List, a sorted array of IDs. The first element of the array is a counter for how many actual IDs are in the list. In the original back-bdb code, IDLs are sorted in ascending order. For libmdb IDLs are sorted in descending order.

typedef MDB_ID2* MDB_ID2L

An ID2L is an ID2 List, a sorted array of ID2s. The first element's mid member is a count of how many actual elements are in the array. The mptr member of the first element is unused. The array is sorted in ascending order by mid.

Function Documentation

unsigned mdb_midl_search ( MDB_IDL  ids,
MDB_ID  id 
)

Search for an ID in an IDL.

Parameters
[in]idsThe IDL to search.
[in]idThe ID to search for.
Returns
The index of the first ID greater than or equal to id.
MDB_IDL mdb_midl_alloc ( int  num)

Allocate an IDL. Allocates memory for an IDL of the given size.

Returns
IDL on success, NULL on failure.
void mdb_midl_free ( MDB_IDL  ids)

Free an IDL.

Parameters
[in]idsThe IDL to free.
void mdb_midl_shrink ( MDB_IDL idp)

Shrink an IDL. Return the IDL to the default size if it has grown larger.

Parameters
[in,out]idpAddress of the IDL to shrink.
int mdb_midl_need ( MDB_IDL idp,
unsigned  num 
)

Make room for num additional elements in an IDL.

Parameters
[in,out]idpAddress of the IDL.
[in]numNumber of elements to make room for.
Returns
0 on success, ENOMEM on failure.
int mdb_midl_append ( MDB_IDL idp,
MDB_ID  id 
)

Append an ID onto an IDL.

Parameters
[in,out]idpAddress of the IDL to append to.
[in]idThe ID to append.
Returns
0 on success, ENOMEM if the IDL is too large.
int mdb_midl_append_list ( MDB_IDL idp,
MDB_IDL  app 
)

Append an IDL onto an IDL.

Parameters
[in,out]idpAddress of the IDL to append to.
[in]appThe IDL to append.
Returns
0 on success, ENOMEM if the IDL is too large.
int mdb_midl_append_range ( MDB_IDL idp,
MDB_ID  id,
unsigned  n 
)

Append an ID range onto an IDL.

Parameters
[in,out]idpAddress of the IDL to append to.
[in]idThe lowest ID to append.
[in]nNumber of IDs to append.
Returns
0 on success, ENOMEM if the IDL is too large.
void mdb_midl_xmerge ( MDB_IDL  idl,
MDB_IDL  merge 
)

Merge an IDL onto an IDL. The destination IDL must be big enough.

Parameters
[in]idlThe IDL to merge into.
[in]mergeThe IDL to merge.
void mdb_midl_sort ( MDB_IDL  ids)

Sort an IDL.

Parameters
[in,out]idsThe IDL to sort.
unsigned mdb_mid2l_search ( MDB_ID2L  ids,
MDB_ID  id 
)

Search for an ID in an ID2L.

Parameters
[in]idsThe ID2L to search.
[in]idThe ID to search for.
Returns
The index of the first ID2 whose mid member is greater than or equal to id.
int mdb_mid2l_insert ( MDB_ID2L  ids,
MDB_ID2 id 
)

Insert an ID2 into a ID2L.

Parameters
[in,out]idsThe ID2L to insert into.
[in]idThe ID2 to insert.
Returns
0 on success, -1 if the ID was already present in the ID2L.
int mdb_mid2l_append ( MDB_ID2L  ids,
MDB_ID2 id 
)

Append an ID2 into a ID2L.

Parameters
[in,out]idsThe ID2L to append into.
[in]idThe ID2 to append.
Returns
0 on success, -2 if the ID2L is too big.