/*
* Build a filter for reading raw stream data.
* This is a null filter to constrain reading to the
* stream length, followed by a decryption filter.
*/
static fz_stream *
pdf_open_raw_filter(fz_stream *chain, pdf_document *xref, pdf_obj *stmobj, int num, int gen)
{
int hascrypt;
int len;
fz_context *ctx = chain->ctx;
/* don't close chain when we close this filter */
fz_keep_stream(chain);
len = pdf_to_int(pdf_dict_gets(stmobj, "Length"));
chain = fz_open_null(chain, len);
fz_try(ctx)
{
hascrypt = pdf_stream_has_crypt(ctx, stmobj);
if (xref->crypt && !hascrypt)
chain = pdf_open_crypt(chain, xref->crypt, num, gen);
}
fz_catch(ctx)
{
fz_close(chain);
fz_rethrow(ctx);
}
return chain;
}
/*
* Build a filter for reading raw stream data.
* This is a null filter to constrain reading to the stream length (and to
* allow for other people accessing the file), followed by a decryption
* filter.
*
* orig_num and orig_gen are used purely to seed the encryption.
*/
static fz_stream *
pdf_open_raw_filter(fz_context *ctx, fz_stream *chain, pdf_document *doc, pdf_obj *stmobj, int num, int orig_num, int orig_gen, int offset)
{
int hascrypt;
int len;
if (num > 0 && num < pdf_xref_len(ctx, doc))
{
pdf_xref_entry *entry = pdf_get_xref_entry(ctx, doc, num);
if (entry->stm_buf)
return fz_open_buffer(ctx, entry->stm_buf);
}
/* don't close chain when we close this filter */
fz_keep_stream(ctx, chain);
len = pdf_to_int(ctx, pdf_dict_get(ctx, stmobj, PDF_NAME_Length));
chain = fz_open_null(ctx, chain, len, offset);
hascrypt = pdf_stream_has_crypt(ctx, stmobj);
if (doc->crypt && !hascrypt)
chain = pdf_open_crypt(ctx, chain, doc->crypt, orig_num, orig_gen);
return chain;
}
/*
* Build a filter for reading raw stream data.
* This is a null filter to constrain reading to the stream length (and to
* allow for other people accessing the file), followed by a decryption
* filter.
*
* orig_num and orig_gen are used purely to seed the encryption.
*/
static fz_stream *
pdf_open_raw_filter(fz_context *ctx, fz_stream *chain, pdf_document *doc, pdf_obj *stmobj, int num, int *orig_num, int *orig_gen, fz_off_t offset)
{
pdf_xref_entry *x = NULL;
int hascrypt;
int len;
if (num > 0 && num < pdf_xref_len(ctx, doc))
{
x = pdf_get_xref_entry(ctx, doc, num);
*orig_num = x->num;
*orig_gen = x->gen;
if (x->stm_buf)
return fz_open_buffer(ctx, x->stm_buf);
}
else
{
/* We only end up here when called from pdf_open_stream_with_offset to parse new format XRef sections. */
/* New style XRef sections must have generation number 0. */
*orig_num = num;
*orig_gen = 0;
}
/* don't close chain when we close this filter */
fz_keep_stream(ctx, chain);
len = pdf_to_int(ctx, pdf_dict_get(ctx, stmobj, PDF_NAME_Length));
chain = fz_open_null(ctx, chain, len, offset);
hascrypt = pdf_stream_has_crypt(ctx, stmobj);
if (doc->crypt && !hascrypt)
chain = pdf_open_crypt(ctx, chain, doc->crypt, *orig_num, *orig_gen);
return chain;
}
/*
* Build a filter for reading raw stream data.
* This is a null filter to constrain reading to the
* stream length, followed by a decryption filter.
*/
static fz_stream *
pdf_open_raw_filter(fz_stream *chain, pdf_xref *xref, fz_obj *stmobj, int num, int gen)
{
int hascrypt;
int len;
/* don't close chain when we close this filter */
fz_keep_stream(chain);
len = fz_to_int(fz_dict_gets(stmobj, "Length"));
chain = fz_open_null(chain, len);
hascrypt = pdf_stream_has_crypt(stmobj);
if (xref->crypt && !hascrypt)
chain = pdf_open_crypt(chain, xref->crypt, num, gen);
return chain;
}
/*
* Construct a filter to decode a stream, without
* constraining to stream length, and without decryption.
*/
fz_stream *
pdf_open_inline_stream(pdf_document *xref, pdf_obj *stmobj, int length, fz_stream *chain, pdf_image_params *imparams)
{
pdf_obj *filters;
pdf_obj *params;
filters = pdf_dict_getsa(stmobj, "Filter", "F");
params = pdf_dict_getsa(stmobj, "DecodeParms", "DP");
/* don't close chain when we close this filter */
fz_keep_stream(chain);
if (pdf_is_name(filters))
return build_filter(chain, xref, filters, params, 0, 0, imparams);
if (pdf_array_len(filters) > 0)
return build_filter_chain(chain, xref, filters, params, 0, 0, imparams);
return fz_open_null(chain, length);
}
/*
* Construct a filter to decode a stream, without
* constraining to stream length, and without decryption.
*/
fz_stream *
pdf_open_inline_stream(fz_stream *chain, pdf_xref *xref, fz_obj *stmobj, int length)
{
fz_obj *filters;
fz_obj *params;
filters = fz_dict_getsa(stmobj, "Filter", "F");
params = fz_dict_getsa(stmobj, "DecodeParms", "DP");
/* don't close chain when we close this filter */
fz_keep_stream(chain);
if (fz_is_name(filters))
return build_filter(chain, xref, filters, params, 0, 0);
if (fz_array_len(filters) > 0)
return build_filter_chain(chain, xref, filters, params, 0, 0);
return fz_open_null(chain, length);
}
/*
* Construct a filter to decode a stream, without
* constraining to stream length, and without decryption.
*/
fz_stream *
pdf_open_inline_stream(fz_context *ctx, pdf_document *doc, pdf_obj *stmobj, int length, fz_stream *chain, fz_compression_params *imparams)
{
pdf_obj *filters;
pdf_obj *params;
filters = pdf_dict_geta(ctx, stmobj, PDF_NAME_Filter, PDF_NAME_F);
params = pdf_dict_geta(ctx, stmobj, PDF_NAME_DecodeParms, PDF_NAME_DP);
/* don't close chain when we close this filter */
fz_keep_stream(ctx, chain);
if (pdf_is_name(ctx, filters))
return build_filter(ctx, chain, doc, filters, params, 0, 0, imparams);
if (pdf_array_len(ctx, filters) > 0)
return build_filter_chain(ctx, chain, doc, filters, params, 0, 0, imparams);
if (imparams)
imparams->type = FZ_IMAGE_RAW;
return fz_open_null(ctx, chain, length, fz_tell(ctx, chain));
}
