941 lines
20 KiB
C
941 lines
20 KiB
C
#include "fitz.h"
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#include "mupdf.h"
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static inline int iswhite(int ch)
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{
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return
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ch == '\000' || ch == '\011' || ch == '\012' ||
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ch == '\014' || ch == '\015' || ch == '\040';
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}
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/*
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* magic version tag and startxref
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*/
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static fz_error
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pdf_load_version(pdf_xref *xref)
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{
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char buf[20];
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fz_seek(xref->file, 0, 0);
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fz_read_line(xref->file, buf, sizeof buf);
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if (memcmp(buf, "%PDF-", 5) != 0)
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return fz_throw("cannot recognize version marker");
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xref->version = atoi(buf + 5) * 10 + atoi(buf + 7);
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return fz_okay;
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}
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static fz_error
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pdf_read_start_xref(pdf_xref *xref)
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{
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unsigned char buf[1024];
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int t, n;
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int i;
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fz_seek(xref->file, 0, 2);
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xref->file_size = fz_tell(xref->file);
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t = MAX(0, xref->file_size - (int)sizeof buf);
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fz_seek(xref->file, t, 0);
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n = fz_read(xref->file, buf, sizeof buf);
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if (n < 0)
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return fz_rethrow(n, "cannot read from file");
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for (i = n - 9; i >= 0; i--)
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{
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if (memcmp(buf + i, "startxref", 9) == 0)
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{
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i += 9;
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while (iswhite(buf[i]) && i < n)
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i ++;
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xref->startxref = atoi((char*)(buf + i));
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return fz_okay;
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}
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}
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return fz_throw("cannot find startxref");
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}
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/*
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* trailer dictionary
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*/
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static fz_error
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pdf_read_old_trailer(pdf_xref *xref, char *buf, int cap)
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{
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fz_error error;
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int len;
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char *s;
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int n;
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int t;
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int tok;
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int c;
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fz_read_line(xref->file, buf, cap);
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if (strncmp(buf, "xref", 4) != 0)
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return fz_throw("cannot find xref marker");
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while (1)
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{
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c = fz_peek_byte(xref->file);
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if (!(c >= '0' && c <= '9'))
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break;
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fz_read_line(xref->file, buf, cap);
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s = buf;
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fz_strsep(&s, " "); /* ignore ofs */
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if (!s)
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return fz_throw("invalid range marker in xref");
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len = atoi(fz_strsep(&s, " "));
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/* broken pdfs where the section is not on a separate line */
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if (s && *s != '\0')
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fz_seek(xref->file, -(2 + (int)strlen(s)), 1);
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t = fz_tell(xref->file);
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if (t < 0)
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return fz_throw("cannot tell in file");
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fz_seek(xref->file, t + 20 * len, 0);
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}
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error = pdf_lex(&tok, xref->file, buf, cap, &n);
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if (error)
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return fz_rethrow(error, "cannot parse trailer");
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if (tok != PDF_TOK_TRAILER)
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return fz_throw("expected trailer marker");
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error = pdf_lex(&tok, xref->file, buf, cap, &n);
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if (error)
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return fz_rethrow(error, "cannot parse trailer");
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if (tok != PDF_TOK_OPEN_DICT)
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return fz_throw("expected trailer dictionary");
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error = pdf_parse_dict(&xref->trailer, xref, xref->file, buf, cap);
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if (error)
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return fz_rethrow(error, "cannot parse trailer");
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return fz_okay;
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}
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static fz_error
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pdf_read_new_trailer(pdf_xref *xref, char *buf, int cap)
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{
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fz_error error;
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error = pdf_parse_ind_obj(&xref->trailer, xref, xref->file, buf, cap, NULL, NULL, NULL);
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if (error)
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return fz_rethrow(error, "cannot parse trailer (compressed)");
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return fz_okay;
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}
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static fz_error
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pdf_read_trailer(pdf_xref *xref, char *buf, int cap)
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{
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fz_error error;
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int c;
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fz_seek(xref->file, xref->startxref, 0);
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while (iswhite(fz_peek_byte(xref->file)))
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fz_read_byte(xref->file);
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c = fz_peek_byte(xref->file);
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if (c == 'x')
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{
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error = pdf_read_old_trailer(xref, buf, cap);
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if (error)
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return fz_rethrow(error, "cannot read trailer");
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}
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else if (c >= '0' && c <= '9')
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{
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error = pdf_read_new_trailer(xref, buf, cap);
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if (error)
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return fz_rethrow(error, "cannot read trailer");
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}
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else
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{
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return fz_throw("cannot recognize xref format: '%c'", c);
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}
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return fz_okay;
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}
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/*
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* xref tables
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*/
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void
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pdf_resize_xref(pdf_xref *xref, int newlen)
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{
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int i;
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xref->table = fz_realloc(xref->table, newlen, sizeof(pdf_xref_entry));
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for (i = xref->len; i < newlen; i++)
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{
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xref->table[i].type = 0;
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xref->table[i].ofs = 0;
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xref->table[i].gen = 0;
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xref->table[i].stm_ofs = 0;
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xref->table[i].obj = NULL;
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}
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xref->len = newlen;
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}
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static fz_error
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pdf_read_old_xref(fz_obj **trailerp, pdf_xref *xref, char *buf, int cap)
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{
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fz_error error;
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int ofs, len;
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char *s;
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int n;
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int tok;
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int i;
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int c;
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fz_read_line(xref->file, buf, cap);
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if (strncmp(buf, "xref", 4) != 0)
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return fz_throw("cannot find xref marker");
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while (1)
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{
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c = fz_peek_byte(xref->file);
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if (!(c >= '0' && c <= '9'))
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break;
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fz_read_line(xref->file, buf, cap);
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s = buf;
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ofs = atoi(fz_strsep(&s, " "));
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len = atoi(fz_strsep(&s, " "));
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/* broken pdfs where the section is not on a separate line */
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if (s && *s != '\0')
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{
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fz_warn("broken xref section. proceeding anyway.");
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fz_seek(xref->file, -(2 + (int)strlen(s)), 1);
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}
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/* broken pdfs where size in trailer undershoots entries in xref sections */
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if (ofs + len > xref->len)
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{
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fz_warn("broken xref section, proceeding anyway.");
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pdf_resize_xref(xref, ofs + len);
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}
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for (i = ofs; i < ofs + len; i++)
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{
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n = fz_read(xref->file, (unsigned char *) buf, 20);
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if (n < 0)
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return fz_rethrow(n, "cannot read xref table");
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if (!xref->table[i].type)
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{
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s = buf;
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/* broken pdfs where line start with white space */
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while (*s != '\0' && iswhite(*s))
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s++;
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xref->table[i].ofs = atoi(s);
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xref->table[i].gen = atoi(s + 11);
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xref->table[i].type = s[17];
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if (s[17] != 'f' && s[17] != 'n' && s[17] != 'o')
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return fz_throw("unexpected xref type: %#x (%d %d R)", s[17], i, xref->table[i].gen);
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}
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}
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}
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error = pdf_lex(&tok, xref->file, buf, cap, &n);
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if (error)
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return fz_rethrow(error, "cannot parse trailer");
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if (tok != PDF_TOK_TRAILER)
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return fz_throw("expected trailer marker");
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error = pdf_lex(&tok, xref->file, buf, cap, &n);
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if (error)
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return fz_rethrow(error, "cannot parse trailer");
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if (tok != PDF_TOK_OPEN_DICT)
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return fz_throw("expected trailer dictionary");
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error = pdf_parse_dict(trailerp, xref, xref->file, buf, cap);
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if (error)
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return fz_rethrow(error, "cannot parse trailer");
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return fz_okay;
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}
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static fz_error
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pdf_read_new_xref_section(pdf_xref *xref, fz_stream *stm, int i0, int i1, int w0, int w1, int w2)
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{
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int i, n;
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if (i0 < 0 || i0 + i1 > xref->len)
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return fz_throw("xref stream has too many entries");
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for (i = i0; i < i0 + i1; i++)
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{
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int a = 0;
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int b = 0;
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int c = 0;
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if (fz_is_eof(stm))
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return fz_throw("truncated xref stream");
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for (n = 0; n < w0; n++)
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a = (a << 8) + fz_read_byte(stm);
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for (n = 0; n < w1; n++)
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b = (b << 8) + fz_read_byte(stm);
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for (n = 0; n < w2; n++)
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c = (c << 8) + fz_read_byte(stm);
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if (!xref->table[i].type)
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{
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int t = w0 ? a : 1;
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xref->table[i].type = t == 0 ? 'f' : t == 1 ? 'n' : t == 2 ? 'o' : 0;
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xref->table[i].ofs = w1 ? b : 0;
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xref->table[i].gen = w2 ? c : 0;
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}
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}
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return fz_okay;
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}
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static fz_error
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pdf_read_new_xref(fz_obj **trailerp, pdf_xref *xref, char *buf, int cap)
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{
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fz_error error;
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fz_stream *stm;
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fz_obj *trailer;
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fz_obj *index;
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fz_obj *obj;
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int num, gen, stm_ofs;
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int size, w0, w1, w2;
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int t;
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error = pdf_parse_ind_obj(&trailer, xref, xref->file, buf, cap, &num, &gen, &stm_ofs);
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if (error)
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return fz_rethrow(error, "cannot parse compressed xref stream object");
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obj = fz_dict_gets(trailer, "Size");
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if (!obj)
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{
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fz_drop_obj(trailer);
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return fz_throw("xref stream missing Size entry (%d %d R)", num, gen);
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}
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size = fz_to_int(obj);
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if (size > xref->len)
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{
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pdf_resize_xref(xref, size);
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}
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if (num < 0 || num >= xref->len)
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{
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fz_drop_obj(trailer);
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return fz_throw("object id (%d %d R) out of range (0..%d)", num, gen, xref->len - 1);
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}
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obj = fz_dict_gets(trailer, "W");
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if (!obj) {
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fz_drop_obj(trailer);
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return fz_throw("xref stream missing W entry (%d %d R)", num, gen);
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}
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w0 = fz_to_int(fz_array_get(obj, 0));
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w1 = fz_to_int(fz_array_get(obj, 1));
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w2 = fz_to_int(fz_array_get(obj, 2));
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index = fz_dict_gets(trailer, "Index");
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error = pdf_open_stream_at(&stm, xref, num, gen, trailer, stm_ofs);
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if (error)
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{
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fz_drop_obj(trailer);
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return fz_rethrow(error, "cannot open compressed xref stream (%d %d R)", num, gen);
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}
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if (!index)
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{
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error = pdf_read_new_xref_section(xref, stm, 0, size, w0, w1, w2);
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if (error)
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{
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fz_close(stm);
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fz_drop_obj(trailer);
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return fz_rethrow(error, "cannot read xref stream (%d %d R)", num, gen);
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}
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}
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else
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{
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for (t = 0; t < fz_array_len(index); t += 2)
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{
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int i0 = fz_to_int(fz_array_get(index, t + 0));
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int i1 = fz_to_int(fz_array_get(index, t + 1));
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error = pdf_read_new_xref_section(xref, stm, i0, i1, w0, w1, w2);
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if (error)
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{
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fz_close(stm);
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fz_drop_obj(trailer);
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return fz_rethrow(error, "cannot read xref stream section (%d %d R)", num, gen);
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}
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}
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}
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fz_close(stm);
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*trailerp = trailer;
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return fz_okay;
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}
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static fz_error
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pdf_read_xref(fz_obj **trailerp, pdf_xref *xref, int ofs, char *buf, int cap)
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{
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fz_error error;
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int c;
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fz_seek(xref->file, ofs, 0);
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while (iswhite(fz_peek_byte(xref->file)))
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fz_read_byte(xref->file);
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c = fz_peek_byte(xref->file);
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if (c == 'x')
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{
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error = pdf_read_old_xref(trailerp, xref, buf, cap);
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if (error)
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return fz_rethrow(error, "cannot read xref (ofs=%d)", ofs);
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}
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else if (c >= '0' && c <= '9')
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{
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error = pdf_read_new_xref(trailerp, xref, buf, cap);
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if (error)
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return fz_rethrow(error, "cannot read xref (ofs=%d)", ofs);
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}
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else
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{
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return fz_throw("cannot recognize xref format");
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}
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return fz_okay;
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}
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static fz_error
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pdf_read_xref_sections(pdf_xref *xref, int ofs, char *buf, int cap)
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{
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fz_error error;
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fz_obj *trailer;
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fz_obj *prev;
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fz_obj *xrefstm;
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error = pdf_read_xref(&trailer, xref, ofs, buf, cap);
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if (error)
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return fz_rethrow(error, "cannot read xref section");
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/* FIXME: do we overwrite free entries properly? */
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xrefstm = fz_dict_gets(trailer, "XRefStm");
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if (xrefstm)
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{
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error = pdf_read_xref_sections(xref, fz_to_int(xrefstm), buf, cap);
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if (error)
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{
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fz_drop_obj(trailer);
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return fz_rethrow(error, "cannot read /XRefStm xref section");
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}
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}
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prev = fz_dict_gets(trailer, "Prev");
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if (prev)
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{
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error = pdf_read_xref_sections(xref, fz_to_int(prev), buf, cap);
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if (error)
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{
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fz_drop_obj(trailer);
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return fz_rethrow(error, "cannot read /Prev xref section");
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}
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}
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fz_drop_obj(trailer);
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return fz_okay;
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}
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|
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/*
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* load xref tables from pdf
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*/
|
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static fz_error
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pdf_load_xref(pdf_xref *xref, char *buf, int bufsize)
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{
|
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fz_error error;
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fz_obj *size;
|
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int i;
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error = pdf_load_version(xref);
|
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if (error)
|
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return fz_rethrow(error, "cannot read version marker");
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error = pdf_read_start_xref(xref);
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if (error)
|
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return fz_rethrow(error, "cannot read startxref");
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error = pdf_read_trailer(xref, buf, bufsize);
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if (error)
|
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return fz_rethrow(error, "cannot read trailer");
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size = fz_dict_gets(xref->trailer, "Size");
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if (!size)
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return fz_throw("trailer missing Size entry");
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pdf_resize_xref(xref, fz_to_int(size));
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error = pdf_read_xref_sections(xref, xref->startxref, buf, bufsize);
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if (error)
|
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return fz_rethrow(error, "cannot read xref");
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/* broken pdfs where first object is not free */
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if (xref->table[0].type != 'f')
|
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return fz_throw("first object in xref is not free");
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|
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/* broken pdfs where object offsets are out of range */
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for (i = 0; i < xref->len; i++)
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{
|
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if (xref->table[i].type == 'n')
|
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if (xref->table[i].ofs <= 0 || xref->table[i].ofs >= xref->file_size)
|
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return fz_throw("object offset out of range: %d (%d 0 R)", xref->table[i].ofs, i);
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if (xref->table[i].type == 'o')
|
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if (xref->table[i].ofs <= 0 || xref->table[i].ofs >= xref->len || xref->table[xref->table[i].ofs].type != 'n')
|
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return fz_throw("invalid reference to an objstm that does not exist: %d (%d 0 R)", xref->table[i].ofs, i);
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}
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return fz_okay;
|
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}
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|
|
/*
|
|
* Initialize and load xref tables.
|
|
* If password is not null, try to decrypt.
|
|
*/
|
|
|
|
fz_error
|
|
pdf_open_xref_with_stream(pdf_xref **xrefp, fz_stream *file, char *password)
|
|
{
|
|
pdf_xref *xref;
|
|
fz_error error;
|
|
fz_obj *encrypt, *id;
|
|
fz_obj *dict, *obj;
|
|
int i, repaired = 0;
|
|
|
|
/* install pdf specific callback */
|
|
fz_resolve_indirect = pdf_resolve_indirect;
|
|
|
|
xref = fz_malloc(sizeof(pdf_xref));
|
|
|
|
memset(xref, 0, sizeof(pdf_xref));
|
|
|
|
xref->file = fz_keep_stream(file);
|
|
|
|
error = pdf_load_xref(xref, xref->scratch, sizeof xref->scratch);
|
|
if (error)
|
|
{
|
|
fz_catch(error, "trying to repair");
|
|
if (xref->table)
|
|
{
|
|
fz_free(xref->table);
|
|
xref->table = NULL;
|
|
xref->len = 0;
|
|
}
|
|
if (xref->trailer)
|
|
{
|
|
fz_drop_obj(xref->trailer);
|
|
xref->trailer = NULL;
|
|
}
|
|
error = pdf_repair_xref(xref, xref->scratch, sizeof xref->scratch);
|
|
if (error)
|
|
{
|
|
pdf_free_xref(xref);
|
|
return fz_rethrow(error, "cannot repair document");
|
|
}
|
|
repaired = 1;
|
|
}
|
|
|
|
encrypt = fz_dict_gets(xref->trailer, "Encrypt");
|
|
id = fz_dict_gets(xref->trailer, "ID");
|
|
if (fz_is_dict(encrypt))
|
|
{
|
|
error = pdf_new_crypt(&xref->crypt, encrypt, id);
|
|
if (error)
|
|
{
|
|
pdf_free_xref(xref);
|
|
return fz_rethrow(error, "cannot decrypt document");
|
|
}
|
|
}
|
|
|
|
if (pdf_needs_password(xref))
|
|
{
|
|
/* Only care if we have a password */
|
|
if (password)
|
|
{
|
|
int okay = pdf_authenticate_password(xref, password);
|
|
if (!okay)
|
|
{
|
|
pdf_free_xref(xref);
|
|
return fz_throw("invalid password");
|
|
}
|
|
}
|
|
}
|
|
|
|
if (repaired)
|
|
{
|
|
int hasroot, hasinfo;
|
|
|
|
error = pdf_repair_obj_stms(xref);
|
|
if (error)
|
|
{
|
|
pdf_free_xref(xref);
|
|
return fz_rethrow(error, "cannot repair document");
|
|
}
|
|
|
|
hasroot = fz_dict_gets(xref->trailer, "Root") != NULL;
|
|
hasinfo = fz_dict_gets(xref->trailer, "Info") != NULL;
|
|
|
|
for (i = 1; i < xref->len; i++)
|
|
{
|
|
if (xref->table[i].type == 0 || xref->table[i].type == 'f')
|
|
continue;
|
|
|
|
error = pdf_load_object(&dict, xref, i, 0);
|
|
if (error)
|
|
{
|
|
fz_catch(error, "ignoring broken object (%d 0 R)", i);
|
|
continue;
|
|
}
|
|
|
|
if (!hasroot)
|
|
{
|
|
obj = fz_dict_gets(dict, "Type");
|
|
if (fz_is_name(obj) && !strcmp(fz_to_name(obj), "Catalog"))
|
|
{
|
|
obj = fz_new_indirect(i, 0, xref);
|
|
fz_dict_puts(xref->trailer, "Root", obj);
|
|
fz_drop_obj(obj);
|
|
}
|
|
}
|
|
|
|
if (!hasinfo)
|
|
{
|
|
if (fz_dict_gets(dict, "Creator") || fz_dict_gets(dict, "Producer"))
|
|
{
|
|
obj = fz_new_indirect(i, 0, xref);
|
|
fz_dict_puts(xref->trailer, "Info", obj);
|
|
fz_drop_obj(obj);
|
|
}
|
|
}
|
|
|
|
fz_drop_obj(dict);
|
|
}
|
|
}
|
|
|
|
*xrefp = xref;
|
|
return fz_okay;
|
|
}
|
|
|
|
void
|
|
pdf_free_xref(pdf_xref *xref)
|
|
{
|
|
int i;
|
|
|
|
if (xref->store)
|
|
pdf_free_store(xref->store);
|
|
|
|
if (xref->table)
|
|
{
|
|
for (i = 0; i < xref->len; i++)
|
|
{
|
|
if (xref->table[i].obj)
|
|
{
|
|
fz_drop_obj(xref->table[i].obj);
|
|
xref->table[i].obj = NULL;
|
|
}
|
|
}
|
|
fz_free(xref->table);
|
|
}
|
|
|
|
if (xref->page_objs)
|
|
{
|
|
for (i = 0; i < xref->page_len; i++)
|
|
fz_drop_obj(xref->page_objs[i]);
|
|
fz_free(xref->page_objs);
|
|
}
|
|
|
|
if (xref->page_refs)
|
|
{
|
|
for (i = 0; i < xref->page_len; i++)
|
|
fz_drop_obj(xref->page_refs[i]);
|
|
fz_free(xref->page_refs);
|
|
}
|
|
|
|
if (xref->file)
|
|
fz_close(xref->file);
|
|
if (xref->trailer)
|
|
fz_drop_obj(xref->trailer);
|
|
if (xref->crypt)
|
|
pdf_free_crypt(xref->crypt);
|
|
|
|
fz_free(xref);
|
|
}
|
|
|
|
void
|
|
pdf_debug_xref(pdf_xref *xref)
|
|
{
|
|
int i;
|
|
printf("xref\n0 %d\n", xref->len);
|
|
for (i = 0; i < xref->len; i++)
|
|
{
|
|
printf("%05d: %010d %05d %c (stm_ofs=%d)\n", i,
|
|
xref->table[i].ofs,
|
|
xref->table[i].gen,
|
|
xref->table[i].type ? xref->table[i].type : '-',
|
|
xref->table[i].stm_ofs);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* compressed object streams
|
|
*/
|
|
|
|
static fz_error
|
|
pdf_load_obj_stm(pdf_xref *xref, int num, int gen, char *buf, int cap)
|
|
{
|
|
fz_error error;
|
|
fz_stream *stm;
|
|
fz_obj *objstm;
|
|
int *numbuf;
|
|
int *ofsbuf;
|
|
|
|
fz_obj *obj;
|
|
int first;
|
|
int count;
|
|
int i, n;
|
|
int tok;
|
|
|
|
error = pdf_load_object(&objstm, xref, num, gen);
|
|
if (error)
|
|
return fz_rethrow(error, "cannot load object stream object (%d %d R)", num, gen);
|
|
|
|
count = fz_to_int(fz_dict_gets(objstm, "N"));
|
|
first = fz_to_int(fz_dict_gets(objstm, "First"));
|
|
|
|
numbuf = fz_calloc(count, sizeof(int));
|
|
ofsbuf = fz_calloc(count, sizeof(int));
|
|
|
|
error = pdf_open_stream(&stm, xref, num, gen);
|
|
if (error)
|
|
{
|
|
error = fz_rethrow(error, "cannot open object stream (%d %d R)", num, gen);
|
|
goto cleanupbuf;
|
|
}
|
|
|
|
for (i = 0; i < count; i++)
|
|
{
|
|
error = pdf_lex(&tok, stm, buf, cap, &n);
|
|
if (error || tok != PDF_TOK_INT)
|
|
{
|
|
error = fz_rethrow(error, "corrupt object stream (%d %d R)", num, gen);
|
|
goto cleanupstm;
|
|
}
|
|
numbuf[i] = atoi(buf);
|
|
|
|
error = pdf_lex(&tok, stm, buf, cap, &n);
|
|
if (error || tok != PDF_TOK_INT)
|
|
{
|
|
error = fz_rethrow(error, "corrupt object stream (%d %d R)", num, gen);
|
|
goto cleanupstm;
|
|
}
|
|
ofsbuf[i] = atoi(buf);
|
|
}
|
|
|
|
fz_seek(stm, first, 0);
|
|
|
|
for (i = 0; i < count; i++)
|
|
{
|
|
fz_seek(stm, first + ofsbuf[i], 0);
|
|
|
|
error = pdf_parse_stm_obj(&obj, xref, stm, buf, cap);
|
|
if (error)
|
|
{
|
|
error = fz_rethrow(error, "cannot parse object %d in stream (%d %d R)", i, num, gen);
|
|
goto cleanupstm;
|
|
}
|
|
|
|
if (numbuf[i] < 1 || numbuf[i] >= xref->len)
|
|
{
|
|
fz_drop_obj(obj);
|
|
error = fz_throw("object id (%d 0 R) out of range (0..%d)", numbuf[i], xref->len - 1);
|
|
goto cleanupstm;
|
|
}
|
|
|
|
if (xref->table[numbuf[i]].type == 'o' && xref->table[numbuf[i]].ofs == num)
|
|
{
|
|
if (xref->table[numbuf[i]].obj)
|
|
fz_drop_obj(xref->table[numbuf[i]].obj);
|
|
xref->table[numbuf[i]].obj = obj;
|
|
}
|
|
else
|
|
{
|
|
fz_drop_obj(obj);
|
|
}
|
|
}
|
|
|
|
fz_close(stm);
|
|
fz_free(ofsbuf);
|
|
fz_free(numbuf);
|
|
fz_drop_obj(objstm);
|
|
return fz_okay;
|
|
|
|
cleanupstm:
|
|
fz_close(stm);
|
|
cleanupbuf:
|
|
fz_free(ofsbuf);
|
|
fz_free(numbuf);
|
|
fz_drop_obj(objstm);
|
|
return error; /* already rethrown */
|
|
}
|
|
|
|
/*
|
|
* object loading
|
|
*/
|
|
|
|
fz_error
|
|
pdf_cache_object(pdf_xref *xref, int num, int gen)
|
|
{
|
|
fz_error error;
|
|
pdf_xref_entry *x;
|
|
int rnum, rgen;
|
|
|
|
if (num < 0 || num >= xref->len)
|
|
return fz_throw("object out of range (%d %d R); xref size %d", num, gen, xref->len);
|
|
|
|
x = &xref->table[num];
|
|
|
|
if (x->obj)
|
|
return fz_okay;
|
|
|
|
if (x->type == 'f')
|
|
{
|
|
x->obj = fz_new_null();
|
|
return fz_okay;
|
|
}
|
|
else if (x->type == 'n')
|
|
{
|
|
fz_seek(xref->file, x->ofs, 0);
|
|
|
|
error = pdf_parse_ind_obj(&x->obj, xref, xref->file, xref->scratch, sizeof xref->scratch,
|
|
&rnum, &rgen, &x->stm_ofs);
|
|
if (error)
|
|
return fz_rethrow(error, "cannot parse object (%d %d R)", num, gen);
|
|
|
|
if (rnum != num)
|
|
return fz_throw("found object (%d %d R) instead of (%d %d R)", rnum, rgen, num, gen);
|
|
|
|
if (xref->crypt)
|
|
pdf_crypt_obj(xref->crypt, x->obj, num, gen);
|
|
}
|
|
else if (x->type == 'o')
|
|
{
|
|
if (!x->obj)
|
|
{
|
|
error = pdf_load_obj_stm(xref, x->ofs, 0, xref->scratch, sizeof xref->scratch);
|
|
if (error)
|
|
return fz_rethrow(error, "cannot load object stream containing object (%d %d R)", num, gen);
|
|
if (!x->obj)
|
|
return fz_throw("object (%d %d R) was not found in its object stream", num, gen);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
return fz_throw("assert: corrupt xref struct");
|
|
}
|
|
|
|
return fz_okay;
|
|
}
|
|
|
|
fz_error
|
|
pdf_load_object(fz_obj **objp, pdf_xref *xref, int num, int gen)
|
|
{
|
|
fz_error error;
|
|
|
|
error = pdf_cache_object(xref, num, gen);
|
|
if (error)
|
|
return fz_rethrow(error, "cannot load object (%d %d R) into cache", num, gen);
|
|
|
|
assert(xref->table[num].obj);
|
|
|
|
*objp = fz_keep_obj(xref->table[num].obj);
|
|
|
|
return fz_okay;
|
|
}
|
|
|
|
fz_obj *
|
|
pdf_resolve_indirect(fz_obj *ref)
|
|
{
|
|
if (fz_is_indirect(ref))
|
|
{
|
|
pdf_xref *xref = fz_get_indirect_xref(ref);
|
|
int num = fz_to_num(ref);
|
|
int gen = fz_to_gen(ref);
|
|
if (xref)
|
|
{
|
|
fz_error error = pdf_cache_object(xref, num, gen);
|
|
if (error)
|
|
{
|
|
fz_catch(error, "cannot load object (%d %d R) into cache", num, gen);
|
|
return ref;
|
|
}
|
|
if (xref->table[num].obj)
|
|
return xref->table[num].obj;
|
|
}
|
|
}
|
|
return ref;
|
|
}
|
|
|
|
/* Replace numbered object -- for use by pdfclean and similar tools */
|
|
void
|
|
pdf_update_object(pdf_xref *xref, int num, int gen, fz_obj *newobj)
|
|
{
|
|
pdf_xref_entry *x;
|
|
|
|
if (num < 0 || num >= xref->len)
|
|
{
|
|
fz_warn("object out of range (%d %d R); xref size %d", num, gen, xref->len);
|
|
return;
|
|
}
|
|
|
|
x = &xref->table[num];
|
|
|
|
if (x->obj)
|
|
fz_drop_obj(x->obj);
|
|
|
|
x->obj = fz_keep_obj(newobj);
|
|
x->type = 'n';
|
|
x->ofs = 0;
|
|
}
|
|
|
|
/*
|
|
* Convenience function to open a file then call pdf_open_xref_with_stream.
|
|
*/
|
|
|
|
fz_error
|
|
pdf_open_xref(pdf_xref **xrefp, const char *filename, char *password)
|
|
{
|
|
fz_error error;
|
|
fz_stream *file;
|
|
|
|
file = fz_open_file(filename);
|
|
if (!file)
|
|
return fz_throw("cannot open file '%s': %s", filename, strerror(errno));
|
|
|
|
error = pdf_open_xref_with_stream(xrefp, file, password);
|
|
if (error)
|
|
return fz_rethrow(error, "cannot load document '%s'", filename);
|
|
|
|
fz_close(file);
|
|
return fz_okay;
|
|
}
|