File: zfproc.c

package info (click to toggle)
ghostscript 8.71~dfsg2-9+squeeze1
  • links: PTS, VCS
  • area: main
  • in suites: squeeze
  • size: 79,896 kB
  • ctags: 80,654
  • sloc: ansic: 501,432; sh: 25,689; python: 4,853; cpp: 3,633; perl: 3,597; tcl: 1,480; makefile: 1,187; lisp: 407; asm: 284; xml: 263; awk: 66; csh: 17; yacc: 15
file content (385 lines) | stat: -rw-r--r-- 10,977 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
/* Copyright (C) 2001-2006 Artifex Software, Inc.
   All Rights Reserved.
  
   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied, modified
   or distributed except as expressly authorized under the terms of that
   license.  Refer to licensing information at http://www.artifex.com/
   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/* $Id: zfproc.c 9043 2008-08-28 22:48:19Z giles $ */
/* Procedure-based filter stream support */
#include "memory_.h"
#include "stat_.h" /* get system header early to avoid name clash on Cygwin */
#include "ghost.h"
#include "oper.h"		/* for ifilter.h */
#include "estack.h"
#include "gsstruct.h"
#include "ialloc.h"
#include "istruct.h"		/* for RELOC_REF_VAR */
#include "stream.h"
#include "strimpl.h"
#include "ifilter.h"
#include "files.h"
#include "store.h"

/* ---------------- Generic ---------------- */

/* GC procedures */
static 
CLEAR_MARKS_PROC(sproc_clear_marks)
{
    stream_proc_state *const pptr = vptr;

    r_clear_attrs(&pptr->proc, l_mark);
    r_clear_attrs(&pptr->data, l_mark);
}
static 
ENUM_PTRS_WITH(sproc_enum_ptrs, stream_proc_state *pptr) return 0;
case 0:
ENUM_RETURN_REF(&pptr->proc);
case 1:
ENUM_RETURN_REF(&pptr->data);
ENUM_PTRS_END
static RELOC_PTRS_WITH(sproc_reloc_ptrs, stream_proc_state *pptr);
RELOC_REF_VAR(pptr->proc);
r_clear_attrs(&pptr->proc, l_mark);
RELOC_REF_VAR(pptr->data);
r_clear_attrs(&pptr->data, l_mark);
RELOC_PTRS_END

/* Structure type for procedure-based streams. */
private_st_stream_proc_state();

/* Allocate and open a procedure-based filter. */
/* The caller must have checked that *sop is a procedure. */
static int
s_proc_init(ref * sop, stream ** psstrm, uint mode,
	    const stream_template * temp, const stream_procs * procs,
	    gs_ref_memory_t *imem)
{
    gs_memory_t *const mem = (gs_memory_t *)imem;
    stream *sstrm = file_alloc_stream(mem, "s_proc_init(stream)");
    stream_proc_state *state = (stream_proc_state *)
	s_alloc_state(mem, &st_sproc_state, "s_proc_init(state)");

    if (sstrm == 0 || state == 0) {
	gs_free_object(mem, state, "s_proc_init(state)");
	/*gs_free_object(mem, sstrm, "s_proc_init(stream)"); *//* just leave it on the file list */
	return_error(e_VMerror);
    }
    s_std_init(sstrm, NULL, 0, procs, mode);
    sstrm->procs.process = temp->process;
    state->template = temp;
    state->memory = mem;
    state->eof = 0;
    state->proc = *sop;
    make_empty_string(&state->data, a_all);
    state->index = 0;
    sstrm->state = (stream_state *) state;
    *psstrm = sstrm;
    return 0;
}

/* Handle an interrupt during a stream operation. */
/* This is logically unrelated to procedure streams, */
/* but it is also associated with the interpreter stream machinery. */
static int
s_handle_intc(i_ctx_t *i_ctx_p, const ref *pstate, int nstate,
	      op_proc_t cont)
{
    int npush = nstate + 2;

    check_estack(npush);
    if (nstate)
	memcpy(esp + 2, pstate, nstate * sizeof(ref));
#if 0				/* **************** */
    {
	int code = gs_interpret_error(e_interrupt, (ref *) (esp + npush));

	if (code < 0)
	    return code;
    }
#else /* **************** */
    npush--;
#endif /* **************** */
    make_op_estack(esp + 1, cont);
    esp += npush;
    return o_push_estack;
}

/* Set default parameter values (actually, just clear pointers). */
static void
s_proc_set_defaults(stream_state * st)
{
    stream_proc_state *const ss = (stream_proc_state *) st;

    make_null(&ss->proc);
    make_null(&ss->data);
}

/* ---------------- Read streams ---------------- */

/* Forward references */
static stream_proc_process(s_proc_read_process);
static int s_proc_read_continue(i_ctx_t *);

/* Stream templates */
static const stream_template s_proc_read_template = {
    &st_sproc_state, NULL, s_proc_read_process, 1, 1,
    NULL, s_proc_set_defaults
};
static const stream_procs s_proc_read_procs = {
    s_std_noavailable, s_std_noseek, s_std_read_reset,
    s_std_read_flush, s_std_null, NULL
};

/* Allocate and open a procedure-based read stream. */
/* The caller must have checked that *sop is a procedure. */
int
sread_proc(ref * sop, stream ** psstrm, gs_ref_memory_t *imem)
{
    int code =
	s_proc_init(sop, psstrm, s_mode_read, &s_proc_read_template,
		    &s_proc_read_procs, imem);

    if (code < 0)
	return code;
    (*psstrm)->end_status = CALLC;
    return code;
}

/* Handle an input request. */
static int
s_proc_read_process(stream_state * st, stream_cursor_read * ignore_pr,
		    stream_cursor_write * pw, bool last)
{
    /* Move data from the string returned by the procedure */
    /* into the stream buffer, or ask for a callback. */
    stream_proc_state *const ss = (stream_proc_state *) st;
    uint count = r_size(&ss->data) - ss->index;

    if (count > 0) {
	uint wcount = pw->limit - pw->ptr;

	if (wcount < count)
	    count = wcount;
	memcpy(pw->ptr + 1, ss->data.value.bytes + ss->index, count);
	pw->ptr += count;
	ss->index += count;
	return 1;
    }
    return (ss->eof ? EOFC : CALLC);
}

/* Handle an exception (INTC or CALLC) from a read stream */
/* whose buffer is empty. */
int
s_handle_read_exception(i_ctx_t *i_ctx_p, int status, const ref * fop,
			const ref * pstate, int nstate, op_proc_t cont)
{
    int npush = nstate + 4;
    stream *ps;

    switch (status) {
	case INTC:
	    return s_handle_intc(i_ctx_p, pstate, nstate, cont);
	case CALLC:
	    break;
	default:
	    return_error(e_ioerror);
    }
    /* Find the stream whose buffer needs refilling. */
    for (ps = fptr(fop); ps->strm != 0;)
	ps = ps->strm;
    check_estack(npush);
    if (nstate)
	memcpy(esp + 2, pstate, nstate * sizeof(ref));
    make_op_estack(esp + 1, cont);
    esp += npush;
    make_op_estack(esp - 2, s_proc_read_continue);
    esp[-1] = *fop;
    r_clear_attrs(esp - 1, a_executable);
    *esp = ((stream_proc_state *) ps->state)->proc;
    return o_push_estack;
}
/* Continue a read operation after returning from a procedure callout. */
/* osp[0] contains the file (pushed on the e-stack by handle_read_status); */
/* osp[-1] contains the new data string (pushed by the procedure). */
/* The top of the e-stack contains the real continuation. */
static int
s_proc_read_continue(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    os_ptr opbuf = op - 1;
    stream *ps;
    stream_proc_state *ss;

    check_file(ps, op);
    check_read_type(*opbuf, t_string);
    while ((ps->end_status = 0, ps->strm) != 0)
	ps = ps->strm;
    ss = (stream_proc_state *) ps->state;
    ss->data = *opbuf;
    ss->index = 0;
    if (r_size(opbuf) == 0)
	ss->eof = true;
    pop(2);
    return 0;
}

/* ---------------- Write streams ---------------- */

/* Forward references */
static stream_proc_flush(s_proc_write_flush);
static stream_proc_process(s_proc_write_process);
static int s_proc_write_continue(i_ctx_t *);

/* Stream templates */
static const stream_template s_proc_write_template = {
    &st_sproc_state, NULL, s_proc_write_process, 1, 1,
    NULL, s_proc_set_defaults
};
static const stream_procs s_proc_write_procs = {
    s_std_noavailable, s_std_noseek, s_std_write_reset,
    s_proc_write_flush, s_std_null, NULL
};

/* Allocate and open a procedure-based write stream. */
/* The caller must have checked that *sop is a procedure. */
int
swrite_proc(ref * sop, stream ** psstrm, gs_ref_memory_t *imem)
{
    return s_proc_init(sop, psstrm, s_mode_write, &s_proc_write_template,
		       &s_proc_write_procs, imem);
}

/* Handle an output request. */
static int
s_proc_write_process(stream_state * st, stream_cursor_read * pr,
		     stream_cursor_write * ignore_pw, bool last)
{
    /* Move data from the stream buffer to the string */
    /* returned by the procedure, or ask for a callback. */
    stream_proc_state *const ss = (stream_proc_state *) st;
    uint rcount = pr->limit - pr->ptr;

    /* if 'last' return CALLC even when rcount == 0. ss->eof terminates */
    if (rcount > 0 || (last && !ss->eof)) {
	uint wcount = r_size(&ss->data) - ss->index;
	uint count = min(rcount, wcount);

	memcpy(ss->data.value.bytes + ss->index, pr->ptr + 1, count);
	pr->ptr += count;
	ss->index += count;
	if (rcount > wcount)
	    return CALLC;
	else if (last) {
	    ss->eof = true;
	    return CALLC;
	} else
	    return 0;
    }
    return ((ss->eof = last) ? EOFC : 0);
}

/* Flush the output.  This is non-standard because it must call the */
/* procedure. */
static int
s_proc_write_flush(stream *s)
{
    int result = s_process_write_buf(s, false);
    stream_proc_state *const ss = (stream_proc_state *)s->state;

    return (result < 0 || ss->index == 0 ? result : CALLC);
}

/* Handle an exception (INTC or CALLC) from a write stream */
/* whose buffer is full. */
int
s_handle_write_exception(i_ctx_t *i_ctx_p, int status, const ref * fop,
			 const ref * pstate, int nstate, op_proc_t cont)
{
    stream *ps;
    stream_proc_state *psst;

    switch (status) {
	case INTC:
	    return s_handle_intc(i_ctx_p, pstate, nstate, cont);
	case CALLC:
	    break;
	default:
	    return_error(e_ioerror);
    }
    /* Find the stream whose buffer needs emptying. */
    for (ps = fptr(fop); ps->strm != 0;)
	ps = ps->strm;
    psst = (stream_proc_state *) ps->state;
    {
	int npush = nstate + 6;

	check_estack(npush);
	if (nstate)
	    memcpy(esp + 2, pstate, nstate * sizeof(ref));
	make_op_estack(esp + 1, cont);
	esp += npush;
	make_op_estack(esp - 4, s_proc_write_continue);
	esp[-3] = *fop;
	r_clear_attrs(esp - 3, a_executable);
	make_bool(esp - 1, !psst->eof);
    }
    esp[-2] = psst->proc;
    *esp = psst->data;
    r_set_size(esp, psst->index);
    return o_push_estack;
}
/* Continue a write operation after returning from a procedure callout. */
/* osp[0] contains the file (pushed on the e-stack by handle_write_status); */
/* osp[-1] contains the new buffer string (pushed by the procedure). */
/* The top of the e-stack contains the real continuation. */
static int
s_proc_write_continue(i_ctx_t *i_ctx_p)
{
    os_ptr op = osp;
    os_ptr opbuf = op - 1;
    stream *ps;
    stream_proc_state *ss;

    check_file(ps, op);
    check_write_type(*opbuf, t_string);
    while (ps->strm != 0) {
	if (ps->end_status == CALLC)
	    ps->end_status = 0;
	ps = ps->strm;
    }
    ps->end_status = 0;
    ss = (stream_proc_state *) ps->state;
    ss->data = *opbuf;
    ss->index = 0;
    pop(2);
    return 0;
}

/* ------ More generic ------ */

/* Test whether a stream is procedure-based. */
bool
s_is_proc(const stream *s)
{
    return (s->procs.process == s_proc_read_process ||
	    s->procs.process == s_proc_write_process);
}

/* ------ Initialization procedure ------ */

const op_def zfproc_op_defs[] =
{
		/* Internal operators */
    {"2%s_proc_read_continue", s_proc_read_continue},
    {"2%s_proc_write_continue", s_proc_write_continue},
    op_def_end(0)
};