Súbor: [Platon] / cpdf / parse.c (stiahnutie)
Revízia 1.14, Wed Oct 16 21:07:43 2002 UTC (21 years, 5 months ago) by lynx
Zmeny od 1.13: +43 -101
[lines]
Ended first phase of coding parse code.
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "cpdf.h"
#include "parse.h"
#include "utils.h"
/* function compute number of locations of char c from buffer to character c
*/
int strlenc(char *buffer, char c, char to)
{
int i = 0;
while (*buffer && *buffer != to) {
if (*buffer == c)
i++;
buffer++;
}
return i;
}
/* function compute lenght of string to char to
*/
int strlento(char *buffer, char to)
{
char *old = buffer;
while (*buffer && *buffer != to)
buffer++;
return buffer - old;
}
/* convert hex to bin
*/
char *hex(char *buffer)
{
char *hex_array, *end;
char num[5] = { '0', 'x', '\0', '\0', '\0' };
int i;
if (*buffer != '<')
return NULL;
if ((i = strlento(buffer + 1, '>') >> 1) == 0)
return NULL;
end = hex_array = (char *) xmalloc(i);
for (buffer++; *buffer != '>'; hex_array++) {
num[2] = *buffer;
if (*(buffer + 1) == '>') {
num[3] = '0';
buffer++;
} else {
num[3] = *(buffer + 1);
buffer += 2;
}
*hex_array = (char) strtoul((char *) &num, NULL, 16);
}
return end;
}
/* interpreter for special characters in name string */
char *name(char *buffer)
{
char *ret, *end;
char num[5] = { '0', 'x', '\0', '\0', '\0' };
if (*buffer != '/')
return NULL;
if (memchr(buffer, '#', MAXNAMELEN) == NULL)
return buffer;
end = ret = (char *) xmalloc(MAXNAMELEN);
while (*buffer && *buffer != ' ') {
if (*buffer == '#') {
num[2] = *(buffer + 1);
num[3] = *(buffer + 2);
*ret = (char) strtoul(num, NULL, 16);
ret++;
buffer += 3;
}
*ret = *buffer;
ret++;
buffer++;
}
return end;
}
char **array(char *buffer)
{
char **ret = NULL, *last;
static char delim[4] = { '[','\0',']','\0' };
int index = 0,len;
last = buffer + 1;
do {
ret = (char **) realloc(ret, (index + 1) * sizeof(char**));
if(*buffer == '[' || *buffer == ']') {
if(*buffer == '[')
ret[index] = &delim[0];
else
ret[index] = &delim[2];
buffer++;
index++;
continue;
}
while (*buffer != ' ' && *buffer != ']' && *buffer != '\n')
buffer++;
len = buffer - last;
ret[index] = (char *) xcalloc(len + 1,sizeof(char));
strncpy(ret[index], last, len);
index++;
if(*buffer != ']')
last = ++buffer;
else
last = buffer;
} while (*buffer != '\n');
return ret;
}
#define BUFLEN 255
void read_obj(long offset)
{
char buffer[BUFLEN];
int obj_num, size = 0;
struct object *obj =
(struct object *) xcalloc(sizeof(struct object), 1);
fseek(fp, offset, SEEK_SET);
fget(buffer, BUFLEN, fp);
sscanf(buffer, "%d ", &obj_num);
fget(buffer, BUFLEN, fp);
if(buffer[0] == '<' && buffer[1] == '<')
fget(buffer,BUFLEN,fp);
while (!strstr(buffer, "endobj")) {
size += strlen(buffer) + 1;
obj->unparsed = realloc(obj->unparsed, size);
strcat(obj->unparsed, buffer);
fget(buffer, BUFLEN, fp);
}
object[obj_num] = obj;
return;
}
/* add object to object structure */
void add_obj(char *s)
{
long offset, old_off;
sscanf(s, "%ld ", &offset);
old_off = ftell(fp);
read_obj(offset);
fseek(fp, old_off, SEEK_SET);
}
/* get offset of start xref table */
long get_startxref(void)
{
char startxref[XREFLINE];
long offset;
int i = XREFLINE - 2;
startxref[XREFLINE - 1] = '\0';
fstat(fp->_fileno, &fpstat);
offset = fpstat.st_size - 8;
fseek(fp, offset, SEEK_SET);
while (1) {
startxref[i] = fgetc(fp);
if (startxref[i] == '\r' || startxref[i] == '\n')
break;
i--;
offset--;
fseek(fp, offset, SEEK_SET);
}
return strtoul(&startxref[i + 1], NULL, 10);
}
void probe_ptree(int num)
{
char *p, **kids, **old;
p = strstr(object[num]->unparsed, "/Page");
if (!p) {
/* error */
return;
}
if (p[5] == 's')
object[num]->type = PAGES;
else {
page_tree[current_page] = num;
current_page++;
return;
}
p = strstr(object[num]->unparsed, "/Kids ");
if (!p) {
/* error */
return;
}
old = kids = array(&p[6]);
for (kids++; **kids != ']'; kids += 3) {
probe_ptree(atoi(*kids));
free(kids[0]);
free(kids[1]);
free(kids[2]);
}
free(old);
return;
}
/* find objects and add it to object structure */
void xref(void)
{
char xref[XREFLINE];
long offset = 0;
offset = get_startxref();
fseek(fp, offset, SEEK_SET);
fget(xref, XREFLINE, fp);
if (!strstr(xref, "xref")) {
/* error */
return;
}
object = NULL;
obj_count = 0;
{
int entry[2];
do {
fget(xref, XREFLINE, fp);
sscanf(xref, "%d %d", &entry[0], &entry[1]);
if (entry[0] + entry[1] > obj_count) {
object = (struct object **)
realloc(object,
entry[0] + entry[1]);
obj_count = entry[0] + entry[1];
}
if (!entry[0])
fseek(fp, XREFLINE, SEEK_CUR);
fget(xref, XREFLINE, fp);
while (strncmp(xref, "trailer", 7)) {
add_obj(&xref[0]);
fget(xref, XREFLINE, fp);
}
fseek(fp, 3, SEEK_CUR);
fget(xref, XREFLINE, fp);
trailer.prev = 0;
while (xref[0] != '>' && xref[1] != '>') {
if (!strncmp(xref, "/Root", 5))
sscanf(xref,
"/Root %d 0 R \n",
&trailer.root);
if (!strncmp(xref, "/Info", 5))
sscanf(xref,
"/Info %d 0 R \n",
&trailer.info);
if (!strncmp(xref, "/Prev", 5))
sscanf(xref, "/Prev %ld",
&trailer.prev);
fget(xref, XREFLINE, fp);
}
if (!trailer.prev)
break;
fseek(fp, trailer.prev, SEEK_SET);
} while (1);
}
return;
}
int parse_catalog(void)
{
char *p;
struct catalog *c;
object[trailer.root]->type = CATALOG;
p = strstr(object[trailer.root]->unparsed, "/Pages");
if (!p) {
/* error */
}
object[trailer.root]->parsed = c =
(struct catalog *) xmalloc(sizeof(struct catalog));
sscanf(p, "/Pages %d 0 R \n", &c->pages);
free(object[trailer.root]->unparsed);
object[trailer.root]->unparsed = NULL;
return c->pages;
}
void parse_pdf(void)
{
int ret, count;
char *p;
xref();
ret = parse_catalog();
p = strstr(object[ret]->unparsed, "/Count ");
sscanf(p, "/Count %d \n", &count);
page_tree = (int *) malloc(count);
current_page = 0;
probe_ptree(ret);
return;
}
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