sparsemap/tests/midl.c

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/** @defgroup idls ID List Management
* @{
*/
/** A generic unsigned ID number. These were entryIDs in back-bdb.
* Preferably it should have the same size as a pointer.
*/
typedef size_t MDB_ID;
/** 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_ID *MDB_IDL;
/* IDL sizes - likely should be even bigger
* limiting factors: sizeof(ID), thread stack size
*/
#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]])
/** Current max length of an #mdb_midl_alloc()ed IDL */
#define MDB_IDL_ALLOCLEN(ids) ((ids)[-1])
/** Append ID to IDL. The IDL must be big enough. */
#define mdb_midl_xappend(idl, id) \
do { \
MDB_ID *xidl = (idl), xlen = ++(xidl[0]); \
xidl[xlen] = (id); \
} while (0)
/** Search for an ID in an IDL.
* @param[in] ids The IDL to search.
* @param[in] id The ID to search for.
* @return The index of the first ID greater than or equal to \b id.
*/
unsigned mdb_midl_search(MDB_IDL ids, MDB_ID id);
/** Allocate an IDL.
* Allocates memory for an IDL of the given size.
* @return IDL on success, NULL on failure.
*/
MDB_IDL mdb_midl_alloc(int num);
/** Free an IDL.
* @param[in] ids The IDL to free.
*/
void mdb_midl_free(MDB_IDL ids);
/** Shrink an IDL.
* Return the IDL to the default size if it has grown larger.
* @param[in,out] idp Address of the IDL to shrink.
*/
void mdb_midl_shrink(MDB_IDL *idp);
/** Shrink an IDL to a specific size.
* Resize the IDL to \b size if it is larger.
* @param[in,out] idp Address of the IDL to shrink.
* @param[in] size Capacity to have once resized.
*/
void mdb_midl_shrink(MDB_IDL *idp);
/** Make room for num additional elements in an IDL.
* @param[in,out] idp Address of the IDL.
* @param[in] num Number of elements to make room for.
* @return 0 on success, ENOMEM on failure.
*/
int mdb_midl_need(MDB_IDL *idp, unsigned num);
/** Append an ID onto an IDL.
* @param[in,out] idp Address of the IDL to append to.
* @param[in] id The ID to append.
* @return 0 on success, ENOMEM if the IDL is too large.
*/
int mdb_midl_append(MDB_IDL *idp, MDB_ID id);
/** Append an IDL onto an IDL.
* @param[in,out] idp Address of the IDL to append to.
* @param[in] app The IDL to append.
* @return 0 on success, ENOMEM if the IDL is too large.
*/
int mdb_midl_append_list(MDB_IDL *idp, MDB_IDL app);
/** Append an ID range onto an IDL.
* @param[in,out] idp Address of the IDL to append to.
* @param[in] id The lowest ID to append.
* @param[in] n Number of IDs to append.
* @return 0 on success, ENOMEM if the IDL is too large.
*/
int mdb_midl_append_range(MDB_IDL *idp, MDB_ID id, unsigned n);
/** Merge an IDL onto an IDL. The destination IDL must be big enough.
* @param[in] idl The IDL to merge into.
* @param[in] merge The IDL to merge.
*/
void mdb_midl_xmerge(MDB_IDL idl, MDB_IDL merge);
/** Sort an IDL.
* @param[in,out] ids The IDL to sort.
*/
void mdb_midl_sort(MDB_IDL ids);
/* midl.c ------------------------------------------------------------------ */
/** @defgroup idls ID List Management
* @{
*/
#define CMP(x, y) ((x) < (y) ? -1 : (x) > (y))
unsigned
mdb_midl_search(MDB_IDL ids, MDB_ID id)
{
/*
* binary search of id in ids
* if found, returns position of id
* if not found, returns first position greater than id
*/
unsigned base = 0;
unsigned cursor = 1;
int val = 0;
unsigned n = ids[0];
while (0 < n) {
unsigned pivot = n >> 1;
cursor = base + pivot + 1;
val = CMP(ids[cursor], id);
if (val < 0) {
n = pivot;
} else if (val > 0) {
base = cursor;
n -= pivot + 1;
} else {
return cursor;
}
}
if (val > 0) {
++cursor;
}
return cursor;
}
int
mdb_midl_insert(MDB_IDL ids, MDB_ID id)
{
unsigned x, i;
x = mdb_midl_search(ids, id);
assert(x > 0);
if (x < 1) {
/* internal error */
return -2;
}
if (x <= ids[0] && ids[x] == id) {
/* duplicate */
assert(0);
return -1;
}
if (++ids[0] >= MDB_IDL_DB_MAX) {
/* no room */
--ids[0];
return -2;
} else {
/* insert id */
for (i = ids[0]; i > x; i--)
ids[i] = ids[i - 1];
ids[x] = id;
}
return 0;
}
inline void
mdb_midl_pop_n(MDB_IDL ids, unsigned n)
{
ids[0] = ids[0] - n;
}
void
mdb_midl_remove_at(MDB_IDL ids, unsigned idx)
{
for (int i = idx - 1; idx < ids[0] - 1;)
ids[++i] = ids[++idx];
ids[0] = ids[0] - 1;
}
void
mdb_midl_remove(MDB_IDL ids, MDB_ID id)
{
unsigned idx = mdb_midl_search(ids, id);
if (idx <= ids[0] && ids[idx] == id)
mdb_midl_remove_at(ids, idx);
}
MDB_IDL
mdb_midl_alloc(int num)
{
MDB_IDL ids = malloc((num + 2) * sizeof(MDB_ID));
if (ids) {
*ids++ = num;
*ids = 0;
}
return ids;
}
void
mdb_midl_free(MDB_IDL ids)
{
if (ids)
free(ids - 1);
}
void
mdb_midl_shrink(MDB_IDL *idp)
{
MDB_IDL ids = *idp;
if (*(--ids) > MDB_IDL_UM_MAX && (ids = realloc(ids, (MDB_IDL_UM_MAX + 2) * sizeof(MDB_ID)))) {
*ids++ = MDB_IDL_UM_MAX;
*idp = ids;
}
}
void
mdb_midl_shrink_to(MDB_IDL *idp, size_t size)
{
MDB_IDL ids = *idp;
if (*(--ids) > size && (ids = realloc(ids, (size + 2) * sizeof(MDB_ID)))) {
*ids++ = size;
*idp = ids;
*idp[0] = *idp[0] > size ? size : *idp[0];
}
}
static int
mdb_midl_grow(MDB_IDL *idp, int num)
{
MDB_IDL idn = *idp - 1;
/* grow it */
idn = realloc(idn, (*idn + num + 2) * sizeof(MDB_ID));
if (!idn)
return ENOMEM;
*idn++ += num;
*idp = idn;
return 0;
}
int
mdb_midl_need(MDB_IDL *idp, unsigned num)
{
MDB_IDL ids = *idp;
num += ids[0];
if (num > ids[-1]) {
num = (num + num / 4 + (256 + 2)) & -256;
if (!(ids = realloc(ids - 1, num * sizeof(MDB_ID))))
return ENOMEM;
*ids++ = num - 2;
*idp = ids;
}
return 0;
}
int
mdb_midl_append(MDB_IDL *idp, MDB_ID id)
{
MDB_IDL ids = *idp;
/* Too big? */
if (ids[0] >= ids[-1]) {
if (mdb_midl_grow(idp, MDB_IDL_UM_MAX))
return ENOMEM;
ids = *idp;
}
ids[0]++;
ids[ids[0]] = id;
return 0;
}
int
mdb_midl_append_list(MDB_IDL *idp, MDB_IDL app)
{
MDB_IDL ids = *idp;
/* Too big? */
if (ids[0] + app[0] >= ids[-1]) {
if (mdb_midl_grow(idp, app[0]))
return ENOMEM;
ids = *idp;
}
memcpy(&ids[ids[0] + 1], &app[1], app[0] * sizeof(MDB_ID));
ids[0] += app[0];
return 0;
}
int
mdb_midl_append_range(MDB_IDL *idp, MDB_ID id, unsigned n)
{
MDB_ID *ids = *idp, len = ids[0];
/* Too big? */
if (len + n > ids[-1]) {
if (mdb_midl_grow(idp, n | MDB_IDL_UM_MAX))
return ENOMEM;
ids = *idp;
}
ids[0] = len + n;
ids += len;
while (n)
ids[n--] = id++;
return 0;
}
void
mdb_midl_xmerge(MDB_IDL idl, MDB_IDL merge)
{
MDB_ID old_id, merge_id, i = merge[0], j = idl[0], k = i + j, total = k;
idl[0] = (MDB_ID)-1; /* delimiter for idl scan below */
old_id = idl[j];
while (i) {
merge_id = merge[i--];
for (; old_id < merge_id; old_id = idl[--j])
idl[k--] = old_id;
idl[k--] = merge_id;
}
idl[0] = total;
}
/* Quicksort + Insertion sort for small arrays */
#define SMALL 8
#define MIDL_SWAP(a, b) \
{ \
itmp = (a); \
(a) = (b); \
(b) = itmp; \
}
void
mdb_midl_sort(MDB_IDL ids)
{
/* Max possible depth of int-indexed tree * 2 items/level */
int istack[sizeof(int) * CHAR_BIT * 2];
int i, j, k, l, ir, jstack;
MDB_ID a, itmp;
ir = (int)ids[0];
l = 1;
jstack = 0;
for (;;) {
if (ir - l < SMALL) { /* Insertion sort */
for (j = l + 1; j <= ir; j++) {
a = ids[j];
for (i = j - 1; i >= 1; i--) {
if (ids[i] >= a)
break;
ids[i + 1] = ids[i];
}
ids[i + 1] = a;
}
if (jstack == 0)
break;
ir = istack[jstack--];
l = istack[jstack--];
} else {
k = (l + ir) >> 1; /* Choose median of left, center, right */
MIDL_SWAP(ids[k], ids[l + 1]);
if (ids[l] < ids[ir]) {
MIDL_SWAP(ids[l], ids[ir]);
}
if (ids[l + 1] < ids[ir]) {
MIDL_SWAP(ids[l + 1], ids[ir]);
}
if (ids[l] < ids[l + 1]) {
MIDL_SWAP(ids[l], ids[l + 1]);
}
i = l + 1;
j = ir;
a = ids[l + 1];
for (;;) {
do
i++;
while (ids[i] > a);
do
j--;
while (ids[j] < a);
if (j < i)
break;
MIDL_SWAP(ids[i], ids[j]);
}
ids[l + 1] = ids[j];
ids[j] = a;
jstack += 2;
if (ir - i + 1 >= j - l) {
istack[jstack] = ir;
istack[jstack - 1] = i;
ir = j - 1;
} else {
istack[jstack] = j - 1;
istack[jstack - 1] = l;
l = i;
}
}
}
}