//

// PDF object functions for PDFio.

//

// Copyright © 2021-2024 by Michael R Sweet.

//

// Licensed under Apache License v2.0. See the file "LICENSE" for more

// information.

//

#include "pdfio-private.h"

//

// Local functions...

//

static bool write_obj_header(pdfio_obj_t *obj);

//

// 'pdfioObjClose()' - Close an object, writing any data as needed to the PDF

// file.

//

bool // O - `true` on success, `false` on failure

pdfioObjClose(pdfio_obj_t *obj) // I - Object

{

// Range check input

if (!obj)

return (false);

// Clear the current object pointer...

obj->pdf->current_obj = NULL;

if (obj->pdf->mode != _PDFIO_MODE_WRITE)

{

// Nothing to do when reading

return (true);

}

// Write what remains for the object...

if (!obj->offset)

{

// Write the object value

if (!write_obj_header(obj))

return (false);

// Write the "endobj" line...

return (_pdfioFilePuts(obj->pdf, "endobj\n"));

}

else if (obj->stream)

{

// Close the stream...

return (pdfioStreamClose(obj->stream));

}

else

{

// Already closed

return (true);

}

}

//

// 'pdfioObjCopy()' - Copy an object to another PDF file.

//

pdfio_obj_t * // O - New object or `NULL` on error

pdfioObjCopy(pdfio_file_t *pdf, // I - PDF file

pdfio_obj_t *srcobj) // I - Object to copy

{

pdfio_obj_t *dstobj; // Destination object

pdfio_stream_t *srcst, // Source stream

*dstst; // Destination stream

char buffer[32768]; // Copy buffer

ssize_t bytes; // Bytes read

PDFIO_DEBUG("pdfioObjCopy(pdf=%p, srcobj=%p(%p))\n", pdf, srcobj, srcobj ? srcobj->pdf : NULL);

// Range check input

if (!pdf || !srcobj)

return (NULL);

// Load the object value if needed...

if (srcobj->value.type == PDFIO_VALTYPE_NONE)

_pdfioObjLoad(srcobj);

// Create the new object...

if ((dstobj = _pdfioFileCreateObj(pdf, srcobj->pdf, NULL)) == NULL)

return (NULL);

// Add new object to the cache of copied objects...

if (!_pdfioFileAddMappedObj(pdf, dstobj, srcobj))

return (NULL);

// Copy the object's value...

if (!_pdfioValueCopy(pdf, &dstobj->value, srcobj->pdf, &srcobj->value))

return (NULL);

if (dstobj->value.type == PDFIO_VALTYPE_DICT)

pdfioDictClear(dstobj->value.value.dict, "Length");

if (srcobj->stream_offset)

{

// Copy stream data...

if ((srcst = pdfioObjOpenStream(srcobj, false)) == NULL)

{

pdfioObjClose(dstobj);

return (NULL);

}

if ((dstst = pdfioObjCreateStream(dstobj, PDFIO_FILTER_NONE)) == NULL)

{

pdfioStreamClose(srcst);

pdfioObjClose(dstobj);

return (NULL);

}

while ((bytes = pdfioStreamRead(srcst, buffer, sizeof(buffer))) > 0)

{

if (!pdfioStreamWrite(dstst, buffer, (size_t)bytes))

{

bytes = -1;

break;

}

}

pdfioStreamClose(srcst);

pdfioStreamClose(dstst);

if (bytes < 0)

return (NULL);

}

else

pdfioObjClose(dstobj);

return (dstobj);

}

//

// 'pdfioObjCreateStream()' - Create an object (data) stream for writing.

//

pdfio_stream_t * // O - Stream or `NULL` on error

pdfioObjCreateStream(

pdfio_obj_t *obj, // I - Object

pdfio_filter_t filter) // I - Type of compression to apply

{

pdfio_obj_t *length_obj = NULL; // Length object, if any

// Range check input

if (!obj || obj->pdf->mode != _PDFIO_MODE_WRITE || obj->value.type != PDFIO_VALTYPE_DICT)

return (NULL);

if (obj->offset)

{

_pdfioFileError(obj->pdf, "Object has already been written.");

return (NULL);

}

if (filter != PDFIO_FILTER_NONE && filter != PDFIO_FILTER_FLATE)

{

_pdfioFileError(obj->pdf, "Unsupported filter value for PDFioObjCreateStream.");

return (NULL);

}

if (obj->pdf->current_obj)

{

_pdfioFileError(obj->pdf, "Another object (%u) is already open.", (unsigned)obj->pdf->current_obj->number);

return (NULL);

}

// Write the header...

if (!_pdfioDictGetValue(obj->value.value.dict, "Length"))

{

if (obj->pdf->output_cb)

{

// Streaming via an output callback, so add a placeholder length object

_pdfio_value_t length_value; // Length value

length_value.type = PDFIO_VALTYPE_NUMBER;

length_value.value.number = 0.0f;

length_obj = _pdfioFileCreateObj(obj->pdf, obj->pdf, &length_value);

pdfioDictSetObj(obj->value.value.dict, "Length", length_obj);

}

else

{

// Need a Length key for the stream, add a placeholder that we can fill in

// later...

pdfioDictSetNumber(obj->value.value.dict, "Length", 0.0);

}

}

if (!write_obj_header(obj))

return (NULL);

if (!_pdfioFilePuts(obj->pdf, "stream\n"))

return (NULL);

obj->stream_offset = _pdfioFileTell(obj->pdf);

obj->pdf->current_obj = obj;

// Return the new stream...

return (_pdfioStreamCreate(obj, length_obj, filter));

}

//

// '_pdfioObjDelete()' - Free memory used by an object.

//

void

_pdfioObjDelete(pdfio_obj_t *obj) // I - Object

{

if (obj)

{

pdfioStreamClose(obj->stream);

if (obj->datafree)

(obj->datafree)(obj->data);

}

free(obj);

}

//

// 'pdfioObjGetArray()' - Get the array associated with an object.

//

pdfio_array_t * // O - Array or `NULL` on error

pdfioObjGetArray(pdfio_obj_t *obj) // I - Object

{

if (!obj)

return (NULL);

if (obj->value.type == PDFIO_VALTYPE_NONE)

_pdfioObjLoad(obj);

if (obj->value.type == PDFIO_VALTYPE_ARRAY)

return (obj->value.value.array);

else

return (NULL);

}

//

// 'pdfioObjGetDict()' - Get the dictionary associated with an object.

//

pdfio_dict_t * // O - Dictionary or `NULL` on error

pdfioObjGetDict(pdfio_obj_t *obj) // I - Object

{

if (!obj)

return (NULL);

if (obj->value.type == PDFIO_VALTYPE_NONE)

_pdfioObjLoad(obj);

if (obj->value.type == PDFIO_VALTYPE_DICT)

return (obj->value.value.dict);

else

return (NULL);

}

//

// '_pdfioObjGetExtension()' - Get the extension pointer for an object.

//

void * // O - Extension data

_pdfioObjGetExtension(pdfio_obj_t *obj) // I - Object

{

return (obj->data);

}

//

// 'pdfioObjGetGeneration()' - Get the object's generation number.

//

unsigned short // O - Generation number (0 to 65535)

pdfioObjGetGeneration(pdfio_obj_t *obj) // I - Object

{

return (obj ? obj->generation : 0);

}

//

// 'pdfioObjGetLength()' - Get the length of the object's (data) stream.

//

size_t // O - Length in bytes or `0` for none

pdfioObjGetLength(pdfio_obj_t *obj) // I - Object

{

size_t length; // Length of stream

pdfio_obj_t *lenobj; // Length object

// Range check input...

if (!obj || !obj->stream_offset || obj->value.type != PDFIO_VALTYPE_DICT)

return (0);

// Try getting the length, directly or indirectly

if ((length = (size_t)pdfioDictGetNumber(obj->value.value.dict, "Length")) > 0)

{

PDFIO_DEBUG("pdfioObjGetLength(obj=%p) returning %lu.\n", obj, (unsigned long)length);

return (length);

}

if ((lenobj = pdfioDictGetObj(obj->value.value.dict, "Length")) == NULL)

{

_pdfioFileError(obj->pdf, "Unable to get length of stream.");

return (0);

}

if (lenobj->value.type == PDFIO_VALTYPE_NONE)

_pdfioObjLoad(lenobj);

if (lenobj->value.type != PDFIO_VALTYPE_NUMBER || lenobj->value.value.number <= 0.0)

{

_pdfioFileError(obj->pdf, "Unable to get length of stream.");

return (0);

}

PDFIO_DEBUG("pdfioObjGetLength(obj=%p) returning %lu.\n", obj, (unsigned long)lenobj->value.value.number);

return ((size_t)lenobj->value.value.number);

}

//

// 'pdfioObjGetName()' - Get the name value associated with an object.

//

const char * // O - Dictionary or `NULL` on error

pdfioObjGetName(pdfio_obj_t *obj) // I - Object

{

if (!obj)

return (NULL);

if (obj->value.type == PDFIO_VALTYPE_NONE)

_pdfioObjLoad(obj);

if (obj->value.type == PDFIO_VALTYPE_NAME)

return (obj->value.value.name);

else

return (NULL);

}

//

// 'pdfioObjGetNumber()' - Get the object's number.

//

size_t // O - Object number (1 to 9999999999)

pdfioObjGetNumber(pdfio_obj_t *obj) // I - Object

{

return (obj ? obj->number : 0);

}

//

// 'pdfioObjGetSubtype()' - Get an object's subtype.

//

// This function returns an object's PDF subtype name, if any. Common subtype

// names include:

//

// - "CIDFontType0": A CID Type0 font

// - "CIDFontType2": A CID TrueType font

// - "Image": An image or image mask

// - "Form": A fillable form

// - "OpenType": An OpenType font

// - "Type0": A composite font

// - "Type1": A PostScript Type1 font

// - "Type3": A PDF Type3 font

// - "TrueType": A TrueType font

//

const char * // O - Object subtype name or `NULL` for none

pdfioObjGetSubtype(pdfio_obj_t *obj) // I - Object

{

pdfio_dict_t *dict; // Object dictionary

if ((dict = pdfioObjGetDict(obj)) == NULL)

return (NULL);

else

return (pdfioDictGetName(dict, "Subtype"));

}

//

// 'pdfioObjGetType()' - Get an object's type.

//

// This function returns an object's PDF type name, if any. Common type names

// include:

//

// - "CMap": A character map for composite fonts

// - "Font": An embedded font (@link pdfioObjGetSubtype@ will tell you the

// font format)

// - "FontDescriptor": A font descriptor

// - "Page": A (visible) page

// - "Pages": A page tree node

// - "Template": An invisible template page

// - "XObject": An image, image mask, or form (@link pdfioObjGetSubtype@ will

// tell you which)

//

const char * // O - Object type name or `NULL` for none

pdfioObjGetType(pdfio_obj_t *obj) // I - Object

{

pdfio_dict_t *dict; // Object dictionary

if ((dict = pdfioObjGetDict(obj)) == NULL)

return (NULL);

else

return (pdfioDictGetName(dict, "Type"));

}

//

// '_pdfioObjLoad()' - Load an object dictionary/value.

//

bool // O - `true` on success, `false` otherwise

_pdfioObjLoad(pdfio_obj_t *obj) // I - Object

{

char line[64], // Line from file

*ptr; // Pointer into line

ssize_t bytes; // Bytes read

_pdfio_token_t tb; // Token buffer/stack

PDFIO_DEBUG("_pdfioObjLoad(obj=%p(%lu)), offset=%lu\n", obj, (unsigned long)obj->number, (unsigned long)obj->offset);

// Seek to the start of the object and read its header...

if (_pdfioFileSeek(obj->pdf, obj->offset, SEEK_SET) != obj->offset)

{

_pdfioFileError(obj->pdf, "Unable to seek to object %lu.", (unsigned long)obj->number);

return (false);

}

if ((bytes = _pdfioFilePeek(obj->pdf, line, sizeof(line) - 1)) < 0)

{

_pdfioFileError(obj->pdf, "Unable to read header for object %lu.", (unsigned long)obj->number);

return (false);

}

line[bytes] = '\0';

PDFIO_DEBUG("_pdfioObjLoad: Header is '%s'.\n", line);

if (strtoimax(line, &ptr, 10) != (intmax_t)obj->number)

{

_pdfioFileError(obj->pdf, "Bad header for object %lu.", (unsigned long)obj->number);

return (false);

}

if (strtol(ptr, &ptr, 10) != (long)obj->generation)

{

_pdfioFileError(obj->pdf, "Bad header for object %lu.", (unsigned long)obj->number);

return (false);

}

while (isspace(*ptr & 255))

ptr ++;

if (strncmp(ptr, "obj", 3) || (ptr[3] && ptr[3] != '<' && ptr[3] != '[' && !isspace(ptr[3] & 255)))

{

_pdfioFileError(obj->pdf, "Bad header for object %lu.", (unsigned long)obj->number);

return (false);

}

ptr += 3;

while (*ptr && isspace(*ptr & 255))

ptr ++;

_pdfioFileConsume(obj->pdf, (size_t)(ptr - line));

// Then grab the object value...

_pdfioTokenInit(&tb, obj->pdf, (_pdfio_tconsume_cb_t)_pdfioFileConsume, (_pdfio_tpeek_cb_t)_pdfioFilePeek, obj->pdf);

if (!_pdfioValueRead(obj->pdf, obj, &tb, &obj->value, 0))

{

_pdfioFileError(obj->pdf, "Unable to read value for object %lu.", (unsigned long)obj->number);

return (false);

}

// Now see if there is an associated stream...

if (!_pdfioTokenGet(&tb, line, sizeof(line)))

{

_pdfioFileError(obj->pdf, "Early end-of-file for object %lu.", (unsigned long)obj->number);

return (false);

}

PDFIO_DEBUG("_pdfioObjLoad: tb.bufptr=%p, tb.bufend=%p, tb.bufptr[0]=0x%02x, tb.bufptr[1]=0x%02x\n", tb.bufptr, tb.bufend, tb.bufptr[0], tb.bufptr[1]);

_pdfioTokenFlush(&tb);

if (!strcmp(line, "stream"))

{

// Yes, this is an embedded stream so save its location...

obj->stream_offset = _pdfioFileTell(obj->pdf);

PDFIO_DEBUG("_pdfioObjLoad: stream_offset=%lu.\n", (unsigned long)obj->stream_offset);

}

// Decrypt as needed...

if (obj->pdf->encryption)

{

PDFIO_DEBUG("_pdfioObjLoad: Decrypting value...\n");

if (!_pdfioValueDecrypt(obj->pdf, obj, &obj->value, 0))

{

PDFIO_DEBUG("_pdfioObjLoad: Failed to decrypt.\n");

return (false);

}

}

PDFIO_DEBUG("_pdfioObjLoad: ");

PDFIO_DEBUG_VALUE(&obj->value);

PDFIO_DEBUG("\n");

return (true);

}

//

// 'pdfioObjOpenStream()' - Open an object's (data) stream for reading.

//

pdfio_stream_t * // O - Stream or `NULL` on error

pdfioObjOpenStream(pdfio_obj_t *obj, // I - Object

bool decode) // I - Decode/decompress data?

{

// Range check input...

if (!obj)

return (NULL);

if (obj->pdf->current_obj)

{

_pdfioFileError(obj->pdf, "Another object (%u) is already open.", (unsigned)obj->pdf->current_obj->number);

return (NULL);

}

// Make sure we've loaded the object dictionary...

if (!obj->value.type)

{

if (!_pdfioObjLoad(obj))

return (NULL);

}

// No stream if there is no dict or offset to a stream...

if (obj->value.type != PDFIO_VALTYPE_DICT || !obj->stream_offset)

return (NULL);

// Open the stream...

obj->pdf->current_obj = obj;

return (_pdfioStreamOpen(obj, decode));

}

//

// '_pdfioObjSetExtension()' - Set extension data for an object.

//

void

_pdfioObjSetExtension(

pdfio_obj_t *obj, // I - Object

void *data, // I - Data

_pdfio_extfree_t datafree) // I - Free function

{

obj->data = data;

obj->datafree = datafree;

}

//

// 'write_obj_header()' - Write the object header...

//

static bool // O - `true` on success, `false` on failure

write_obj_header(pdfio_obj_t *obj) // I - Object

{

obj->offset = _pdfioFileTell(obj->pdf);

if (!_pdfioFilePrintf(obj->pdf, "%lu %u obj\n", (unsigned long)obj->number, obj->generation))

return (false);

if (!_pdfioValueWrite(obj->pdf, obj, &obj->value, &obj->length_offset))

return (false);

return (_pdfioFilePuts(obj->pdf, "\n"));

}