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Rework debug functions, start xref stream support.

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This commit is contained in:
Michael R Sweet
2021-05-06 09:51:48 -04:00
parent c0b18a7e4f
commit d2a0484d93
5 changed files with 244 additions and 122 deletions
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238
pdfio-file.c
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@@ -517,6 +517,10 @@ load_xref(pdfio_file_t *pdf, // I - PDF file
char line[1024], // Line from file
*ptr; // Pointer into line
_pdfio_value_t trailer; // Trailer dictionary
intmax_t number, // Object number
num_objects, // Number of objects
offset; // Offset in file
int generation; // Generation number
while (!done)
@@ -533,103 +537,153 @@ load_xref(pdfio_file_t *pdf, // I - PDF file
return (false);
}
if (strcmp(line, "xref"))
if (isdigit(line[0] & 255) && strlen(line) > 4 && !strcmp(line + strlen(line) - 4, " obj"))
{
// Cross-reference stream
pdfio_obj_t *obj; // Object
pdfio_array_t *w_array; // W array
size_t w[3]; // Size of each cross-reference field
size_t w_total; // Total length
pdfio_stream_t *st; // Stream with
unsigned char buffer[32]; // Read buffer
if ((number = strtoimax(line, &ptr, 10)) < 1)
{
_pdfioFileError(pdf, "Bad xref table header '%s'.", line);
return (false);
}
if ((generation = (int)strtol(ptr, &ptr, 10)) < 0 || generation > 65535)
{
_pdfioFileError(pdf, "Bad xref table header '%s'.", line);
return (false);
}
while (isspace(*ptr & 255))
ptr ++;
if (strcmp(ptr, "obj"))
{
_pdfioFileError(pdf, "Bad xref table header '%s'.", line);
return (false);
}
if ((obj = add_obj(pdf, (size_t)number, (unsigned short)generation, xref_offset)) == NULL)
{
_pdfioFileError(pdf, "Unable to allocate memory for object.");
return (false);
}
if (!_pdfioValueRead(pdf, &trailer))
{
_pdfioFileError(pdf, "Unable to read cross-reference stream dictionary.");
return (false);
}
else if (trailer.type != PDFIO_VALTYPE_DICT)
{
_pdfioFileError(pdf, "Cross-reference stream does not have a dictionary.");
return (false);
}
obj->value = trailer;
// TODO: read stream
}
else if (!strcmp(line, "xref"))
{
// Read the xref tables
while (_pdfioFileGets(pdf, line, sizeof(line)))
{
if (!strcmp(line, "trailer"))
break;
if (sscanf(line, "%jd%jd", &number, &num_objects) != 2)
{
_pdfioFileError(pdf, "Malformed xref table section '%s'.", line);
return (false);
}
// Read this group of objects...
for (; num_objects > 0; num_objects --, number ++)
{
// Read a line from the file and validate it...
if (_pdfioFileRead(pdf, line, 20) != 20)
return (false);
line[20] = '\0';
if (strcmp(line + 18, "\r\n") && strcmp(line + 18, " \n") && strcmp(line + 18, " \r"))
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
line[18] = '\0';
// Parse the line
if ((offset = strtoimax(line, &ptr, 10)) < 0)
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if ((generation = (int)strtol(ptr, &ptr, 10)) < 0 || generation > 65535)
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if (*ptr != ' ')
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
ptr ++;
if (*ptr != 'f' && *ptr != 'n')
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if (*ptr == 'f')
continue; // Don't care about free objects...
// Create a placeholder for the object in memory...
if (pdfioFileFindObject(pdf, (size_t)number))
continue; // Don't replace newer object...
if (!add_obj(pdf, (size_t)number, (unsigned short)generation, offset))
return (false);
}
}
if (strcmp(line, "trailer"))
{
_pdfioFileError(pdf, "Missing trailer.");
return (false);
}
if (!_pdfioValueRead(pdf, &trailer))
{
_pdfioFileError(pdf, "Unable to read trailer dictionary.");
return (false);
}
else if (trailer.type != PDFIO_VALTYPE_DICT)
{
_pdfioFileError(pdf, "Trailer is not a dictionary.");
return (false);
}
}
else
{
_pdfioFileError(pdf, "Bad xref table header '%s'.", line);
return (false);
}
// Read the xref tables
while (_pdfioFileGets(pdf, line, sizeof(line)))
{
intmax_t number, // Object number
num_objects; // Number of objects
if (!strcmp(line, "trailer"))
break;
if (sscanf(line, "%jd%jd", &number, &num_objects) != 2)
{
_pdfioFileError(pdf, "Malformed xref table section '%s'.", line);
return (false);
}
// Read this group of objects...
for (; num_objects > 0; num_objects --, number ++)
{
intmax_t offset; // Offset in file
int generation; // Generation number
// Read a line from the file and validate it...
if (_pdfioFileRead(pdf, line, 20) != 20)
return (false);
line[20] = '\0';
if (strcmp(line + 18, "\r\n") && strcmp(line + 18, " \n") && strcmp(line + 18, " \r"))
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
line[18] = '\0';
// Parse the line
if ((offset = strtoimax(line, &ptr, 10)) < 0)
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if ((generation = (int)strtol(ptr, &ptr, 10)) < 0 || generation > 65535)
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if (*ptr != ' ')
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
ptr ++;
if (*ptr != 'f' && *ptr != 'n')
{
_pdfioFileError(pdf, "Malformed xref table entry '%s'.", line);
return (false);
}
if (*ptr == 'f')
continue; // Don't care about free objects...
// Create a placeholder for the object in memory...
if (pdfioFileFindObject(pdf, (size_t)number))
continue; // Don't replace newer object...
if (!add_obj(pdf, (size_t)number, (unsigned short)generation, offset))
return (false);
}
}
if (strcmp(line, "trailer"))
{
_pdfioFileError(pdf, "Missing trailer.");
return (false);
}
if (!_pdfioValueRead(pdf, &trailer))
{
_pdfioFileError(pdf, "Unable to read trailer dictionary.");
return (false);
}
else if (trailer.type != PDFIO_VALTYPE_DICT)
{
_pdfioFileError(pdf, "Trailer is not a dictionary.");
return (false);
}
PDFIO_DEBUG("load_xref: Contents of trailer dictionary:\n");
PDFIO_DEBUG_DICT(trailer.value.dict, "load_xref");
PDFIO_DEBUG("load_xref: ");
PDFIO_DEBUG_VALUE(&trailer);
PDFIO_DEBUG("\n");
if (!pdf->trailer)
{
@@ -648,7 +702,7 @@ load_xref(pdfio_file_t *pdf, // I - PDF file
pdf->id_array = pdfioDictGetArray(pdf->trailer, "ID");
}
if ((xref_offset = (off_t)pdfioDictGetNumber(pdf->trailer, "Prev")) <= 0)
if ((xref_offset = (off_t)pdfioDictGetNumber(trailer.value.dict, "Prev")) <= 0)
done = true;
}