Sweden-Number/server/atom.c

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/*
* Server-side atom management
*
* Copyright (C) 1999, 2000 Alexandre Julliard
* Copyright (C) 2000 Turchanov Sergei
*/
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include "unicode.h"
#include "request.h"
#include "object.h"
#define HASH_SIZE 37
#define MAX_ATOM_LEN 255
#define MAX_ATOMS 0x4000
struct atom_entry
{
struct atom_entry *next; /* hash table list */
struct atom_entry *prev; /* hash table list */
int atom; /* atom handle */
int count; /* reference count */
int hash; /* string hash */
WCHAR str[1]; /* atom string */
};
struct atom_table
{
struct object obj; /* object header */
int count; /* count of atom handles */
int last; /* last handle in-use */
struct atom_entry **handles; /* atom handles */
struct atom_entry *entries[HASH_SIZE]; /* hash table entries */
};
static void atom_table_dump( struct object *obj, int verbose );
static void atom_table_destroy( struct object *obj );
static const struct object_ops atom_table_ops =
{
sizeof(struct atom_table), /* size */
atom_table_dump, /* dump */
no_add_queue, /* add_queue */
NULL, /* remove_queue */
NULL, /* signaled */
NULL, /* satified */
NULL, /* get_poll_events */
NULL, /* poll_event */
no_read_fd, /* get_read_fd */
no_write_fd, /* get_write_fd */
no_flush, /* flush */
no_get_file_info, /* get_file_info */
atom_table_destroy /* destroy */
};
static struct atom_table *global_table;
/* copy an atom name to a temporary area */
static const WCHAR *copy_name( const WCHAR *str )
{
static WCHAR buffer[MAX_ATOM_LEN+1];
WCHAR *p = buffer;
while (p < buffer + sizeof(buffer) - 1) if (!(*p++ = *str++)) break;
*p = 0;
return buffer;
}
/* create an atom table */
static struct atom_table *create_table(void)
{
struct atom_table *table;
if ((table = alloc_object( &atom_table_ops, -1 )))
{
table->count = 64;
table->last = -1;
memset( table->entries, 0, sizeof(table->entries) );
if ((table->handles = mem_alloc( sizeof(*table->handles) * table->count )))
return table;
release_object( table );
table = NULL;
}
return table;
}
/* retrieve an entry pointer from its atom */
static struct atom_entry *get_atom_entry( struct atom_table *table, int atom )
{
struct atom_entry *entry = NULL;
if (table && (atom >= 0) && (atom <= table->last)) entry = table->handles[atom];
if (!entry) set_error( STATUS_INVALID_HANDLE );
return entry;
}
/* add an atom entry in the table and return its handle */
static int add_atom_entry( struct atom_table *table, struct atom_entry *entry )
{
int i;
for (i = 0; i <= table->last; i++)
if (!table->handles[i]) goto found;
if (i == table->count)
{
struct atom_entry **new_table = NULL;
int new_size = table->count + table->count / 2;
if (new_size > MAX_ATOMS) new_size = MAX_ATOMS;
if (new_size > table->count)
new_table = realloc( table->handles, sizeof(*table->handles) * new_size );
if (!new_table)
{
set_error( STATUS_NO_MEMORY );
return -1;
}
table->count = new_size;
table->handles = new_table;
}
table->last = i;
found:
table->handles[i] = entry;
entry->atom = i;
return i;
}
/* compute the hash code for a string */
static int atom_hash( const WCHAR *str )
{
int i;
WCHAR hash = 0;
for (i = 0; str[i]; i++) hash ^= towupper(str[i]) + i;
return hash % HASH_SIZE;
}
/* dump an atom table */
static void atom_table_dump( struct object *obj, int verbose )
{
int i;
struct atom_table *table = (struct atom_table *)obj;
assert( obj->ops == &atom_table_ops );
fprintf( stderr, "Atom table size=%d\n", table->last + 1 );
if (!verbose) return;
for (i = 0; i <= table->last; i++)
{
struct atom_entry *entry = table->handles[i];
if (!entry) continue;
fprintf( stderr, " %5d: ref=%d hash=%d \"", i, entry->count, entry->hash );
dump_strW( entry->str, strlenW(entry->str), stderr, "\"\"");
fprintf( stderr, "\"\n" );
}
}
/* destroy the atom table */
static void atom_table_destroy( struct object *obj )
{
int i;
struct atom_table *table = (struct atom_table *)obj;
assert( obj->ops == &atom_table_ops );
for (i = 0; i <= table->last; i++) free( table->handles[i] );
free( table->handles );
}
/* find an atom entry in its hash list */
static struct atom_entry *find_atom_entry( struct atom_table *table, const WCHAR *str, int hash )
{
struct atom_entry *entry = table->entries[hash];
while (entry)
{
if (!strcmpiW( entry->str, str )) break;
entry = entry->next;
}
return entry;
}
/* close the atom table; used on server exit */
void close_atom_table(void)
{
if (global_table) release_object( global_table );
}
/* add an atom to the table */
static int add_atom( struct atom_table *table, const WCHAR *str )
{
struct atom_entry *entry;
int hash = atom_hash( str );
int atom = -1;
if (!*str)
{
set_error( STATUS_OBJECT_NAME_INVALID );
return -1;
}
if ((entry = find_atom_entry( table, str, hash ))) /* exists already */
{
entry->count++;
return entry->atom;
}
if ((entry = mem_alloc( sizeof(*entry) + strlenW(str) * sizeof(WCHAR) )))
{
if ((atom = add_atom_entry( table, entry )) != -1)
{
entry->prev = NULL;
if ((entry->next = table->entries[hash])) entry->next->prev = entry;
table->entries[hash] = entry;
entry->count = 1;
entry->hash = hash;
strcpyW( entry->str, str );
}
else free( entry );
}
else set_error( STATUS_NO_MEMORY );
return atom;
}
/* delete an atom from the table */
static void delete_atom( struct atom_table *table, int atom )
{
struct atom_entry *entry = get_atom_entry( table, atom );
if (entry && !--entry->count)
{
if (entry->next) entry->next->prev = entry->prev;
if (entry->prev) entry->prev->next = entry->next;
else table->entries[entry->hash] = entry->next;
table->handles[atom] = NULL;
free( entry );
}
}
/* find an atom in the table */
static int find_atom( struct atom_table *table, const WCHAR *str )
{
struct atom_entry *entry;
if (table && ((entry = find_atom_entry( table, str, atom_hash(str) )))) return entry->atom;
if (!*str) set_error( STATUS_OBJECT_NAME_INVALID );
else set_error( STATUS_OBJECT_NAME_NOT_FOUND );
return -1;
}
/* get an atom name and refcount*/
static int get_atom_name( struct atom_table *table, int atom, WCHAR *str )
{
int count = -1;
struct atom_entry *entry = get_atom_entry( table, atom );
if (entry)
{
strcpyW( str, entry->str );
count = entry->count;
}
return count;
}
/* add a global atom */
DECL_HANDLER(add_atom)
{
if (!global_table) global_table = create_table();
if (global_table) req->atom = add_atom( global_table, copy_name( req->name ) );
}
/* delete a global atom */
DECL_HANDLER(delete_atom)
{
delete_atom( global_table, req->atom );
}
/* find a global atom */
DECL_HANDLER(find_atom)
{
req->atom = find_atom( global_table, copy_name( req->name ) );
}
/* get global atom name */
DECL_HANDLER(get_atom_name)
{
req->name[0] = 0;
req->count = get_atom_name( global_table, req->atom, req->name );
}