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 <string.h>
#include "unicode.h"
#include "request.h"
#include "object.h"
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#include "process.h"
#define HASH_SIZE 37
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#define MIN_HASH_SIZE 4
#define MAX_HASH_SIZE 0x200
#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 */
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int entries_count; /* humber of hash entries */
struct atom_entry **entries; /* 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_get_fd, /* get_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, size_t len )
{
static WCHAR buffer[MAX_ATOM_LEN+1];
if (len > MAX_ATOM_LEN*sizeof(WCHAR))
{
set_error( STATUS_INVALID_PARAMETER );
return NULL;
}
memcpy( buffer, str, len );
buffer[len / sizeof(WCHAR)] = 0;
return buffer;
}
/* create an atom table */
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static struct atom_table *create_table(int entries_count)
{
struct atom_table *table;
if ((table = alloc_object( &atom_table_ops, -1 )))
{
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if ((entries_count < MIN_HASH_SIZE) ||
(entries_count > MAX_HASH_SIZE)) entries_count = HASH_SIZE;
table->entries_count = entries_count;
if (!(table->entries = malloc( sizeof(*table->entries) * table->entries_count )))
{
set_error( STATUS_NO_MEMORY );
goto fail;
}
memset( table->entries, 0, sizeof(*table->entries) * table->entries_count );
table->count = 64;
table->last = -1;
if ((table->handles = mem_alloc( sizeof(*table->handles) * table->count )))
return table;
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fail:
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 */
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static int atom_hash( struct atom_table *table, const WCHAR *str )
{
int i;
WCHAR hash = 0;
for (i = 0; str[i]; i++) hash ^= toupperW(str[i]) + i;
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return hash % table->entries_count;
}
/* 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 );
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fprintf( stderr, "Atom table size=%d entries=%d\n",
table->last + 1, table->entries_count );
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 );
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if (table->handles)
{
for (i = 0; i <= table->last; i++) free( table->handles[i] );
free( table->handles );
}
if (table->entries) free( table->entries );
}
/* 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;
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int hash = atom_hash( table, 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;
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if (table && ((entry = find_atom_entry( table, str, atom_hash(table, 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 size_t get_atom_name( struct atom_table *table, int atom,
WCHAR *str, size_t maxsize, int *count )
{
size_t len = 0;
struct atom_entry *entry = get_atom_entry( table, atom );
*count = -1;
if (entry)
{
*count = entry->count;
len = strlenW( entry->str ) * sizeof(WCHAR);
if (len <= maxsize) memcpy( str, entry->str, len );
else
{
set_error( STATUS_BUFFER_OVERFLOW );
len = 0;
}
}
return len;
}
/* add a global atom */
DECL_HANDLER(add_atom)
{
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struct atom_table **table_ptr = req->local ? &current->process->atom_table : &global_table;
if (!*table_ptr) *table_ptr = create_table(0);
if (*table_ptr)
{
const WCHAR *name = copy_name( get_req_data(req), get_req_data_size(req) );
if (name) req->atom = add_atom( *table_ptr, name );
}
}
/* delete a global atom */
DECL_HANDLER(delete_atom)
{
delete_atom( req->local ? current->process->atom_table : global_table, req->atom );
}
/* find a global atom */
DECL_HANDLER(find_atom)
{
const WCHAR *name = copy_name( get_req_data(req), get_req_data_size(req) );
if (name)
req->atom = find_atom( req->local ? current->process->atom_table : global_table, name );
}
/* get global atom name */
DECL_HANDLER(get_atom_name)
{
WCHAR *name = get_req_data(req);
size_t size = get_atom_name( req->local ? current->process->atom_table : global_table,
req->atom, name, get_req_data_size(req), &req->count );
set_req_data_size( req, size );
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}
/* init the process atom table */
DECL_HANDLER(init_atom_table)
{
if (!current->process->atom_table)
current->process->atom_table = create_table( req->entries );
}