dany/pdfio
1
0
Fork 0
mirror of https://github.com/michaelrsweet/pdfio.git synced 2025-07-15 21:40:11 +02:00
Code Issues Packages Projects Releases Wiki Activity

Rework token reading to be separate from the PDF file so we can add support

Browse Source 
for compressed object streams.
This commit is contained in:
Michael R Sweet
2021-05-08 07:38:44 -04:00
parent 923409ceff
commit 9a919d478f
9 changed files with 211 additions and 166 deletions
Download Patch File Download Diff File Expand all files Collapse all files

220
pdfio-token.c
View File

@ -44,26 +44,99 @@
#define PDFIO_DELIM_CHARS "<>(){}[]/%"
//
// Types...
//
typedef struct _pdfio_tbuffer_s // Token reading buffer
{
unsigned char buffer[32], // Buffer
*bufptr, // Pointer into buffer
*bufend; // Last valid byte in buffer
_pdfio_tpeek_cb_t peek_cb; // Peek callback
_pdfio_tconsume_cb_t consume_cb; // Consume callback
void *data; // Callback data
} _pdfio_tbuffer_t;
//
// Local functions...
//
static int get_char(_pdfio_tbuffer_t *tb);
static int get_char(_pdfio_token_t *tb);
//
// '_pdfioTokenClear()' - Clear the token stack.
//
void
_pdfioTokenClear(_pdfio_token_t *tb) // I - Token buffer/stack
{
PDFIO_DEBUG("_pdfioTokenClear(tb=%p)\n", tb);
while (tb->num_tokens > 0)
{
tb->num_tokens --;
free(tb->tokens[tb->num_tokens]);
tb->tokens[tb->num_tokens] = NULL;
}
}
//
// '_pdfioTokenGet()' - Get a token.
//
bool // O - `true` on success, `false` on failure
_pdfioTokenGet(_pdfio_token_t *tb, // I - Token buffer/stack
char *buffer, // I - String buffer
size_t bufsize) // I - Size of string buffer
{
// See if we have a token waiting on the stack...
if (tb->num_tokens > 0)
{
// Yes, return it...
tb->num_tokens --;
strncpy(buffer, tb->tokens[tb->num_tokens], bufsize - 1);
buffer[bufsize - 1] = '\0';
PDFIO_DEBUG("_pdfioTokenGet(tb=%p, buffer=%p, bufsize=%u): Popping '%s' from stack.\n", tb, buffer, (unsigned)bufsize, buffer);
free(tb->tokens[tb->num_tokens]);
tb->tokens[tb->num_tokens] = NULL;
return (true);
}
// No, read a new one...
return (_pdfioTokenRead(tb, buffer, bufsize));
}
//
// '_pdfioTokenInit()' - Initialize a token buffer/stack.
//
void
_pdfioTokenInit(
_pdfio_token_t *ts, // I - Token buffer/stack
pdfio_file_t *pdf, // I - PDF file
_pdfio_tconsume_cb_t consume_cb, // I - Consume callback
_pdfio_tpeek_cb_t peek_cb, // I - Peek callback
void *cb_data) // I - Callback data
{
// Zero everything out and then initialize key pointers...
memset(ts, 0, sizeof(_pdfio_token_t));
ts->pdf = pdf;
ts->consume_cb = consume_cb;
ts->peek_cb = peek_cb;
ts->cb_data = cb_data;
ts->bufptr = ts->buffer;
ts->bufend = ts->buffer;
}
//
// '_pdfioTokenPush()' - Push a token on the token stack.
//
void
_pdfioTokenPush(_pdfio_token_t *tb, // I - Token buffer/stack
const char *token) // I - Token to push
{
if (tb->num_tokens < (sizeof(tb->tokens) / sizeof(tb->tokens[0])))
{
if ((tb->tokens[tb->num_tokens ++] = strdup(token)) == NULL)
tb->num_tokens --;
}
}
//
@ -71,19 +144,14 @@ static int get_char(_pdfio_tbuffer_t *tb);
//
bool // O - `true` on success, `false` on failure
_pdfioTokenRead(
pdfio_file_t *pdf, // I - PDF file
char *buffer, // I - String buffer
size_t bufsize, // I - Size of string buffer
_pdfio_tpeek_cb_t peek_cb, // I - "peek" callback
_pdfio_tconsume_cb_t consume_cb, // I - "consume" callback
void *data) // I - Callback data
_pdfioTokenRead(_pdfio_token_t *tb, // I - Token buffer/stack
char *buffer, // I - String buffer
size_t bufsize) // I - Size of string buffer
{
_pdfio_tbuffer_t tb; // Token buffer
int ch; // Character
char *bufptr, // Pointer into buffer
*bufend, // End of buffer
state = '\0'; // Current state
int ch; // Character
char *bufptr, // Pointer into buffer
*bufend, // End of buffer
state = '\0'; // Current state
//
@ -99,21 +167,16 @@ _pdfioTokenRead(
// - 'N' for number
// Read the next token, skipping any leading whitespace...
memset(&tb, 0, sizeof(tb));
tb.peek_cb = peek_cb;
tb.consume_cb = consume_cb;
tb.data = data;
bufptr = buffer;
bufend = buffer + bufsize - 1;
// Skip leading whitespace...
while ((ch = get_char(&tb)) != EOF)
while ((ch = get_char(tb)) != EOF)
{
if (ch == '%')
{
// Skip comment
while ((ch = get_char(&tb)) != EOF)
while ((ch = get_char(tb)) != EOF)
{
if (ch == '\n' || ch == '\r')
break;
@ -147,14 +210,14 @@ _pdfioTokenRead(
switch (state)
{
case '(' : // Literal string
while ((ch = get_char(&tb)) != EOF && ch != ')')
while ((ch = get_char(tb)) != EOF && ch != ')')
{
if (ch == '\\')
{
// Quoted character...
int i; // Looping var
switch (ch = get_char(&tb))
switch (ch = get_char(tb))
{
case '0' : // Octal character escape
case '1' :
@ -166,13 +229,13 @@ _pdfioTokenRead(
case '7' :
for (ch -= '0', i = 0; i < 2; i ++)
{
int tch = get_char(&tb); // Next char
int tch = get_char(tb); // Next char
if (tch >= '0' && tch <= '7')
ch = (char)((ch << 3) | (tch - '0'));
else
{
tb.bufptr --;
tb->bufptr --;
break;
}
}
@ -204,7 +267,7 @@ _pdfioTokenRead(
break;
default :
_pdfioFileError(pdf, "Unknown escape '\\%c' in literal string.", ch);
_pdfioFileError(tb->pdf, "Unknown escape '\\%c' in literal string.", ch);
return (false);
}
}
@ -217,25 +280,25 @@ _pdfioTokenRead(
else
{
// Out of space
_pdfioFileError(pdf, "Token too large.");
_pdfioFileError(tb->pdf, "Token too large.");
return (false);
}
}
if (ch != ')')
{
_pdfioFileError(pdf, "Unterminated string literal.");
_pdfioFileError(tb->pdf, "Unterminated string literal.");
return (false);
}
break;
case 'K' : // keyword
while ((ch = get_char(&tb)) != EOF && !isspace(ch))
while ((ch = get_char(tb)) != EOF && !isspace(ch))
{
if (strchr(PDFIO_DELIM_CHARS, ch) != NULL)
{
// End of keyword...
tb.bufptr --;
tb->bufptr --;
break;
}
else if (bufptr < bufend)
@ -246,19 +309,19 @@ _pdfioTokenRead(
else
{
// Out of space...
_pdfioFileError(pdf, "Token too large.");
_pdfioFileError(tb->pdf, "Token too large.");
return (false);
}
}
break;
case 'N' : // number
while ((ch = get_char(&tb)) != EOF && !isspace(ch))
while ((ch = get_char(tb)) != EOF && !isspace(ch))
{
if (!isdigit(ch) && ch != '.')
{
// End of number...
tb.bufptr --;
tb->bufptr --;
break;
}
else if (bufptr < bufend)
@ -269,19 +332,19 @@ _pdfioTokenRead(
else
{
// Out of space...
_pdfioFileError(pdf, "Token too large.");
_pdfioFileError(tb->pdf, "Token too large.");
return (false);
}
}
break;
case '/' : // "/name"
while ((ch = get_char(&tb)) != EOF && !isspace(ch))
while ((ch = get_char(tb)) != EOF && !isspace(ch))
{
if (strchr(PDFIO_DELIM_CHARS, ch) != NULL)
{
// End of keyword...
tb.bufptr --;
tb->bufptr --;
break;
}
else if (ch == '#')
@ -291,11 +354,11 @@ _pdfioTokenRead(
for (i = 0, ch = 0; i < 2; i ++)
{
int tch = get_char(&tb);
int tch = get_char(tb);
if (!isxdigit(tch & 255))
{
_pdfioFileError(pdf, "Bad # escape in name.");
_pdfioFileError(tb->pdf, "Bad # escape in name.");
return (false);
}
else if (isdigit(tch))
@ -312,14 +375,14 @@ _pdfioTokenRead(
else
{
// Out of space
_pdfioFileError(pdf, "Token too large.");
_pdfioFileError(tb->pdf, "Token too large.");
return (false);
}
}
break;
case '<' : // Potential hex string
if ((ch = get_char(&tb)) == '<')
if ((ch = get_char(tb)) == '<')
{
// Dictionary delimiter
*bufptr++ = (char)ch;
@ -327,11 +390,11 @@ _pdfioTokenRead(
}
else if (!isspace(ch & 255) && !isxdigit(ch & 255))
{
_pdfioFileError(pdf, "Syntax error: '<%c'", ch);
_pdfioFileError(tb->pdf, "Syntax error: '<%c'", ch);
return (false);
}
while ((ch = get_char(&tb)) != EOF && ch != '>')
while ((ch = get_char(tb)) != EOF && ch != '>')
{
if (isxdigit(ch))
{
@ -343,46 +406,65 @@ _pdfioTokenRead(
else
{
// Too large
_pdfioFileError(pdf, "Token too large.");
_pdfioFileError(tb->pdf, "Token too large.");
return (false);
}
}
else if (!isspace(ch))
{
_pdfioFileError(pdf, "Invalid hex string character '%c'.", ch);
_pdfioFileError(tb->pdf, "Invalid hex string character '%c'.", ch);
return (false);
}
}
if (ch == EOF)
{
_pdfioFileError(pdf, "Unterminated hex string.");
_pdfioFileError(tb->pdf, "Unterminated hex string.");
return (false);
}
break;
case '>' : // Dictionary
if ((ch = get_char(&tb)) == '>')
if ((ch = get_char(tb)) == '>')
{
*bufptr++ = '>';
}
else
{
_pdfioFileError(pdf, "Syntax error: '>%c'.", ch);
_pdfioFileError(tb->pdf, "Syntax error: '>%c'.", ch);
return (false);
}
break;
}
while (tb.bufptr < tb.bufend && isspace(*(tb.bufptr)))
tb.bufptr ++;
while (tb->bufptr < tb->bufend && isspace(*(tb->bufptr)))
tb->bufptr ++;
if (tb.bufptr > tb.buffer)
(consume_cb)(data, (size_t)(tb.bufptr - tb.buffer));
if (tb->bufptr > tb->buffer)
{
size_t remaining = (size_t)(tb->bufend - tb->bufptr);
// Remaining bytes in buffer
// Consume what we've used...
(tb->consume_cb)(tb->cb_data, (size_t)(tb->bufptr - tb->buffer));
if (remaining > 0)
{
// Shuffle remaining bytes for next call...
memmove(tb->buffer, tb->bufptr, remaining);
tb->bufptr = tb->buffer;
tb->bufend = tb->buffer + remaining;
}
else
{
// Nothing left, reset pointers...
tb->bufptr = tb->bufend = tb->buffer;
}
}
*bufptr = '\0';
PDFIO_DEBUG("_pdfioTokenRead(pdf=%p, ...): Read '%s'.\n", pdf, buffer);
PDFIO_DEBUG("_pdfioTokenRead: Read '%s'.\n", buffer);
return (bufptr > buffer);
}
@ -393,7 +475,7 @@ _pdfioTokenRead(
//
static int // O - Character or `EOF` on end-of-file
get_char(_pdfio_tbuffer_t *tb) // I - Token buffer
get_char(_pdfio_token_t *tb) // I - Token buffer
{
ssize_t bytes; // Bytes peeked
@ -403,10 +485,10 @@ get_char(_pdfio_tbuffer_t *tb) // I - Token buffer
{
// Consume previous bytes...
if (tb->bufend > tb->buffer)
(tb->consume_cb)(tb->data, (size_t)(tb->bufend - tb->buffer));
(tb->consume_cb)(tb->cb_data, (size_t)(tb->bufend - tb->buffer));
// Peek new bytes...
if ((bytes = (tb->peek_cb)(tb->data, tb->buffer, sizeof(tb->buffer))) < 0)
if ((bytes = (tb->peek_cb)(tb->cb_data, tb->buffer, sizeof(tb->buffer))) <= 0)
{
tb->bufptr = tb->bufend = tb->buffer;
return (EOF);