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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:53:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:53:35 +0000 |
commit | 69c6a41ffb878ef98c9378ed4b1634a404cfaa7f (patch) | |
tree | b2a4f704565d62fbb129ab9dc3b35977c50e6e7f /src/contrib/lmdb/midl.c | |
parent | Initial commit. (diff) | |
download | knot-upstream/2.7.6.tar.xz knot-upstream/2.7.6.zip |
Adding upstream version 2.7.6.upstream/2.7.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/contrib/lmdb/midl.c')
-rw-r--r-- | src/contrib/lmdb/midl.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/src/contrib/lmdb/midl.c b/src/contrib/lmdb/midl.c new file mode 100644 index 0000000..7b2b77e --- /dev/null +++ b/src/contrib/lmdb/midl.c @@ -0,0 +1,359 @@ +/** @file midl.c + * @brief ldap bdb back-end ID List functions */ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software <http://www.openldap.org/>. + * + * Copyright 2000-2018 The OpenLDAP Foundation. + * Portions Copyright 2001-2018 Howard Chu, Symas Corp. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted only as authorized by the OpenLDAP + * Public License. + * + * A copy of this license is available in the file LICENSE in the + * top-level directory of the distribution or, alternatively, at + * <http://www.OpenLDAP.org/license.html>. + */ + +#include <limits.h> +#include <string.h> +#include <stdlib.h> +#include <errno.h> +#include <sys/types.h> +#include "midl.h" + +/** @defgroup internal LMDB Internals + * @{ + */ +/** @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 0 ) { + ++cursor; + } + return cursor; +} + +#if 0 /* superseded by append/sort */ +int mdb_midl_insert( MDB_IDL ids, MDB_ID id ) +{ + unsigned x, i; + + x = mdb_midl_search( ids, id ); + assert( x 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; +} +#endif + +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; + } +} + +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; + } + } + } +} + +unsigned mdb_mid2l_search( MDB_ID2L 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 = (unsigned)ids[0].mid; + + while( 0 < n ) { + unsigned pivot = n >> 1; + cursor = base + pivot + 1; + val = CMP( id, ids[cursor].mid ); + + 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_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id ) +{ + unsigned x, i; + + x = mdb_mid2l_search( ids, id->mid ); + + if( x < 1 ) { + /* internal error */ + return -2; + } + + if ( x <= ids[0].mid && ids[x].mid == id->mid ) { + /* duplicate */ + return -1; + } + + if ( ids[0].mid >= MDB_IDL_UM_MAX ) { + /* too big */ + return -2; + + } else { + /* insert id */ + ids[0].mid++; + for (i=(unsigned)ids[0].mid; i>x; i--) + ids[i] = ids[i-1]; + ids[x] = *id; + } + + return 0; +} + +int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id ) +{ + /* Too big? */ + if (ids[0].mid >= MDB_IDL_UM_MAX) { + return -2; + } + ids[0].mid++; + ids[ids[0].mid] = *id; + return 0; +} + +/** @} */ +/** @} */ |