1/*
2 * font server atom manipulations
3 */
4/*
5Copyright 1987, 1998  The Open Group
6
7Permission to use, copy, modify, distribute, and sell this software and its
8documentation for any purpose is hereby granted without fee, provided that
9the above copyright notice appear in all copies and that both that
10copyright notice and this permission notice appear in supporting
11documentation.
12
13The above copyright notice and this permission notice shall be included in
14all copies or substantial portions of the Software.
15
16THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
19OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
20AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22
23Except as contained in this notice, the name of The Open Group shall not be
24used in advertising or otherwise to promote the sale, use or other dealings
25in this Software without prior written authorization from The Open Group.
26 * Copyright 1990, 1991 Network Computing Devices;
27 * Portions Copyright 1987 by Digital Equipment Corporation
28 *
29 * Permission to use, copy, modify, distribute, and sell this software and its
30 * documentation for any purpose is hereby granted without fee, provided that
31 * the above copyright notice appear in all copies and that both that
32 * copyright notice and this permission notice appear in supporting
33 * documentation, and that the names of Network Computing Devices,
34 * or Digital not be used in advertising or
35 * publicity pertaining to distribution of the software without specific,
36 * written prior permission.  Network Computing Devices, or Digital
37 * make no representations about the
38 * suitability of this software for any purpose.  It is provided "as is"
39 * without express or implied warranty.
40 *
41 * NETWORK COMPUTING DEVICES, AND DIGITAL DISCLAIM ALL WARRANTIES WITH
42 * REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
43 * AND FITNESS, IN NO EVENT SHALL NETWORK COMPUTING DEVICES, OR DIGITAL BE
44 * LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
45 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
46 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
47 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
48 *
49 */
50
51#include "config.h"
52
53#include "misc.h"
54#include "fsresource.h"
55#include "difs.h"
56
57#define InitialTableSize 100
58#define	FSA_LAST_PREDEFINED	0 /* only None is predefined */
59
60typedef struct _Node {
61    struct _Node *left,
62               *right;
63    Atom        a;
64    unsigned int fingerPrint;
65    char       *string;
66}           NodeRec, *NodePtr;
67
68static Atom lastAtom = None;
69static NodePtr atomRoot = (NodePtr) NULL;
70static unsigned long tableLength;
71static NodePtr *nodeTable;
72
73Atom
74MakeAtom(const char *string, unsigned int len, Bool makeit)
75{
76    register NodePtr *np;
77    unsigned    i;
78    int         comp;
79    register unsigned int fp = 0;
80
81    np = &atomRoot;
82    for (i = 0; i < (len + 1) / 2; i++) {
83	fp = fp * 27 + string[i];
84	fp = fp * 27 + string[len - 1 - i];
85    }
86    while (*np != (NodePtr) NULL) {
87	if (fp < (*np)->fingerPrint)
88	    np = &((*np)->left);
89	else if (fp > (*np)->fingerPrint)
90	    np = &((*np)->right);
91	else {			/* now start testing the strings */
92	    comp = strncmp(string, (*np)->string, len);
93	    if ((comp < 0) || ((comp == 0) && (len < strlen((*np)->string))))
94		np = &((*np)->left);
95	    else if (comp > 0)
96		np = &((*np)->right);
97	    else
98		return (*np)->a;
99	}
100    }
101    if (makeit) {
102	register NodePtr nd;
103
104	nd = (NodePtr) FSalloc(sizeof(NodeRec));
105	if (!nd)
106	    return BAD_RESOURCE;
107#if FSA_LAST_PREDEFINED > 0
108	if (lastAtom < FSA_LAST_PREDEFINED) {
109	    nd->string = string;
110	} else
111#endif
112	{
113	    nd->string = (char *) FSalloc(len + 1);
114	    if (!nd->string) {
115		FSfree(nd);
116		return BAD_RESOURCE;
117	    }
118	    strncpy(nd->string, string, len);
119	    nd->string[len] = 0;
120	}
121	if ((lastAtom + 1) >= tableLength) {
122	    NodePtr    *table;
123
124	    table = (NodePtr *) FSreallocarray(nodeTable, tableLength,
125                                               (2 * sizeof(NodePtr)));
126	    if (!table) {
127		if (nd->string != string)
128		    FSfree(nd->string);
129		FSfree(nd);
130		return BAD_RESOURCE;
131	    }
132	    tableLength <<= 1;
133	    nodeTable = table;
134	}
135	*np = nd;
136	nd->left = nd->right = (NodePtr) NULL;
137	nd->fingerPrint = fp;
138	nd->a = (++lastAtom);
139	*(nodeTable + lastAtom) = nd;
140	return nd->a;
141    } else
142	return None;
143}
144
145int
146ValidAtom(Atom atom)
147{
148    return (atom != None) && (atom <= lastAtom);
149}
150
151const char *
152NameForAtom(Atom atom)
153{
154    NodePtr     node;
155
156    if (atom > lastAtom)
157	return NULL;
158    if ((node = nodeTable[atom]) == (NodePtr) NULL)
159	return NULL;
160    return node->string;
161}
162
163static void
164atom_error(void)
165{
166    FatalError("initializing atoms\n");
167}
168
169static void
170free_atom(NodePtr patom)
171{
172    if (patom->left)
173	free_atom(patom->left);
174    if (patom->right)
175	free_atom(patom->right);
176    if (patom->a > FSA_LAST_PREDEFINED)
177	FSfree(patom->string);
178    FSfree(patom);
179}
180
181static void
182free_all_atoms(void)
183{
184    if (atomRoot == (NodePtr) NULL)
185	return;
186    free_atom(atomRoot);
187    atomRoot = (NodePtr) NULL;
188    FSfree(nodeTable);
189    nodeTable = (NodePtr *) NULL;
190    lastAtom = None;
191}
192
193void
194InitAtoms(void)
195{
196    free_all_atoms();
197    tableLength = InitialTableSize;
198    nodeTable = (NodePtr *) FSallocarray(InitialTableSize, sizeof(NodePtr));
199    if (!nodeTable)
200	atom_error();
201    nodeTable[None] = (NodePtr) NULL;
202    lastAtom = FSA_LAST_PREDEFINED;
203}
204