/* * Copyright 1993, 1995 Christopher Seiwald. * * This file is part of Jam - see jam.c for Copyright information. */ # include "jam.h" # include "hash.h" /* * hash.c - simple in-memory hashing routines * * External routines: * * hashinit() - initialize a hash table, returning a handle * hashitem() - find a record in the table, and optionally enter a new one * hashdone() - free a hash table, given its handle * * Internal routines: * * hashrehash() - resize and rebuild hp->tab, the hash table * * 4/29/93 - ensure ITEM's are aligned */ char *hashsccssid="@(#)hash.c 1.14 () 6/20/88"; /* Header attached to all data items entered into a hash table. */ struct hashhdr { struct item *next; int keyval; /* for quick comparisons */ } ; /* This structure overlays the one handed to hashenter(). */ /* It's actual size is given to hashinit(). */ struct hashdata { char *key; /* rest of user data */ } ; typedef struct item { struct hashhdr hdr; struct hashdata data; } ITEM ; # define MAX_LISTS 32 struct hash { /* * the hash table, just an array of item pointers */ struct { int nel; ITEM **base; } tab; int bloat; /* tab.nel / items.nel */ int inel; /* initial number of elements */ /* * the array of records, maintained by these routines * essentially a microallocator */ struct { int more; /* how many more ITEMs fit in lists[ list ] */ char *next; /* where to put more ITEMs in lists[ list ] */ int datalen; /* length of records in this hash table */ int size; /* sizeof( ITEM ) + aligned datalen */ int nel; /* total ITEMs held by all lists[] */ int list; /* index into lists[] */ struct { int nel; /* total ITEMs held by this list */ char *base; /* base of ITEMs array */ } lists[ MAX_LISTS ]; } items; char *name; /* just for hashstats() */ } ; static void hashrehash(); static void hashstat(); /* * hashitem() - find a record in the table, and optionally enter a new one */ int hashitem( hp, data, enter ) register struct hash *hp; HASHDATA **data; { ITEM **base; register ITEM *i; char *b = (*data)->key; int keyval; if( enter && !hp->items.more ) hashrehash( hp ); if( !enter && !hp->items.nel ) return 0; keyval = *b; while( *b ) keyval = keyval * 2147059363 + *b++; keyval &= 0x7FFFFFFF; base = hp->tab.base + ( keyval % hp->tab.nel ); for( i = *base; i; i = i->hdr.next ) if( keyval == i->hdr.keyval && !strcmp( i->data.key, (*data)->key ) ) { *data = &i->data; return !0; } if( enter ) { i = (ITEM *)hp->items.next; hp->items.next += hp->items.size; hp->items.more--; memcpy( (char *)&i->data, (char *)*data, hp->items.datalen ); i->hdr.keyval = keyval; i->hdr.next = *base; *base = i; *data = &i->data; } return 0; } /* * hashrehash() - resize and rebuild hp->tab, the hash table */ static void hashrehash( hp ) register struct hash *hp; { int i = ++hp->items.list; hp->items.more = i ? 2 * hp->items.nel : hp->inel; hp->items.next = (char *)malloc( hp->items.more * hp->items.size ); hp->items.lists[i].nel = hp->items.more; hp->items.lists[i].base = hp->items.next; hp->items.nel += hp->items.more; if( hp->tab.base ) free( (char *)hp->tab.base ); hp->tab.nel = hp->items.nel * hp->bloat; hp->tab.base = (ITEM **)malloc( hp->tab.nel * sizeof(ITEM **) ); memset( (char *)hp->tab.base, '\0', hp->tab.nel * sizeof( ITEM * ) ); for( i = 0; i < hp->items.list; i++ ) { int nel = hp->items.lists[i].nel; char *next = hp->items.lists[i].base; for( ; nel--; next += hp->items.size ) { register ITEM *i = (ITEM *)next; ITEM **ip = hp->tab.base + i->hdr.keyval % hp->tab.nel; i->hdr.next = *ip; *ip = i; } } } /* --- */ # define ALIGNED(x) ( ( x + sizeof( ITEM ) - 1 ) & ~( sizeof( ITEM ) - 1 ) ) /* * hashinit() - initialize a hash table, returning a handle */ struct hash * hashinit( datalen, name ) char *name; { struct hash *hp = (struct hash *)malloc( sizeof( *hp ) ); hp->bloat = 3; hp->tab.nel = 0; hp->tab.base = (ITEM **)0; hp->items.more = 0; hp->items.datalen = datalen; hp->items.size = sizeof( struct hashhdr ) + ALIGNED( datalen ); hp->items.list = -1; hp->items.nel = 0; hp->inel = 11; hp->name = name; return hp; } /* * hashdone() - free a hash table, given its handle */ void hashdone( hp ) struct hash *hp; { int i; if( !hp ) return; if( DEBUG_MEM ) hashstat( hp ); if( hp->tab.base ) free( (char *)hp->tab.base ); for( i = 0; i <= hp->items.list; i++ ) free( hp->items.lists[i].base ); free( (char *)hp ); } /* ---- */ static void hashstat( hp ) struct hash *hp; { ITEM **tab = hp->tab.base; int nel = hp->tab.nel; int count = 0; int sets = 0; int run = ( tab[ nel - 1 ] != (ITEM *)0 ); int i, here; for( i = nel; i > 0; i-- ) { if( here = ( *tab++ != (ITEM *)0 ) ) count++; if( here && !run ) sets++; run = here; } printf( "%s table: %d+%d+%d (%dK+%dK) items+table+hash, %f density\n", hp->name, count, hp->items.nel, hp->tab.nel, hp->items.nel * hp->items.size / 1024, hp->tab.nel * sizeof( ITEM ** ) / 1024, (float)count / (float)sets ); }
# | Change | User | Description | Committed | |
---|---|---|---|---|---|
#6 | 9907 | Perforce staff |
Build jam without so many warnings on macosxx86_64. p4transfer.py: Transferred from production |
||
#5 | 2851 | rmg |
Minor Cray porting: make hashitem()'s key value unsigned so we're guaranteed no integer overflows. Porting change. === computer:1666: Change 41931 by seiwald@play-seiwald on 2003/02/25 13:10:31 |
||
#4 | 2493 | rmg |
Rewrite the past: update all jam's source with comments to reflect changes since about 2.3, very early 2001. Whitespace only change. === computer:1666: Change 37660 by seiwald@play-seiwald on 2002/11/06 22:41:35 Note: I regenerated jamgram.c on my linux 7.3 system prior to the submit, since patch was so unhappy trying to lay down the changes from Christopher's change. Presumably this is just due to different yacc/bison/whatever particulars on the system where Christopher made the changes originally. - rmg |
||
#3 | 2491 | rmg |
Some consting in jam to make it more compilable by C++ compilers. No functional change. === computer:1666: Change 37433 by perforce@perforce on 2002/10/30 16:08:51 Recreational const-ing of jam, for compilers that don't allow "string" to be passed as a non-const char *. This included a few places where we were modifying what could possibly have been read-only storage, oddly enough. No functional change. === computer:1666: Change 37602 by seiwald@play-seiwald on 2002/11/04 17:25:40 |
||
#2 | 486 | Perforce staff |
Jam 2.3. See RELNOTES for a list of changes from 2.2.x. Just about every source file was touched when jam got ANSI-fied. |
||
#1 | 2 | laura | Add Jam/MR 2.2 source |