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tesseract/ccutil/scanutils.cpp

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// Copyright 2006 Google Inc.
// All Rights Reserved.
// Author: renn
//
// The fscanf, vfscanf and creat functions are implemented so that their
// functionality is mostly like their stdio counterparts. However, currently
// these functions do not use any buffering, making them rather slow.
// File streams are thus processed one character at a time.
// Although the implementations of the scanf functions do lack a few minor
// features, they should be sufficient for their use in tesseract.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifdef HAVE_CONFIG_H
#include "config_auto.h"
#endif
#include <ctype.h>
#include <math.h>
#include <stdarg.h>
#include <stddef.h>
#include <string.h>
#include <limits.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "scanutils.h"
#include "tprintf.h"
// workaround for "'off_t' was not declared in this scope" with -std=c++11
#if !defined(HAVE_OFF_T)
typedef long off_t;
#endif // off_t
enum Flags {
FL_SPLAT = 0x01, // Drop the value, do not assign
FL_INV = 0x02, // Character-set with inverse
FL_WIDTH = 0x04, // Field width specified
FL_MINUS = 0x08, // Negative number
};
enum Ranks {
RANK_CHAR = -2,
RANK_SHORT = -1,
RANK_INT = 0,
RANK_LONG = 1,
RANK_LONGLONG = 2,
RANK_PTR = INT_MAX // Special value used for pointers
};
const enum Ranks kMinRank = RANK_CHAR;
const enum Ranks kMaxRank = RANK_LONGLONG;
const enum Ranks kIntMaxRank = RANK_LONGLONG;
const enum Ranks kSizeTRank = RANK_LONG;
const enum Ranks kPtrDiffRank = RANK_LONG;
enum Bail {
BAIL_NONE = 0, // No error condition
BAIL_EOF, // Hit EOF
BAIL_ERR // Conversion mismatch
};
// Helper functions ------------------------------------------------------------
inline size_t LongBit() {
return CHAR_BIT * sizeof(long);
}
static inline int
SkipSpace(FILE *s) {
int p;
while (isspace(p = fgetc(s)));
ungetc(p, s); // Make sure next char is available for reading
return p;
}
static inline void
SetBit(unsigned long *bitmap, unsigned int bit) {
bitmap[bit/LongBit()] |= 1UL << (bit%LongBit());
}
static inline int
TestBit(unsigned long *bitmap, unsigned int bit) {
return static_cast<int>(bitmap[bit/LongBit()] >> (bit%LongBit())) & 1;
}
static inline int DigitValue(int ch, int base) {
if (ch >= '0' && ch <= '9') {
if (base >= 10 || ch <= '7')
return ch-'0';
} else if (ch >= 'A' && ch <= 'Z' && base == 16) {
return ch-'A'+10;
} else if (ch >= 'a' && ch <= 'z' && base == 16) {
return ch-'a'+10;
}
return -1;
}
// IO (re-)implementations -----------------------------------------------------
uintmax_t streamtoumax(FILE* s, int base) {
int minus = 0;
uintmax_t v = 0;
int d, c = 0;
for (c = fgetc(s);
isspace(static_cast<unsigned char>(c)) && (c != EOF);
c = fgetc(s)) {}
// Single optional + or -
if (c == '-' || c == '+') {
minus = (c == '-');
c = fgetc(s);
}
// Assign correct base
if (base == 0) {
if (c == '0') {
c = fgetc(s);
if (c == 'x' || c == 'X') {
base = 16;
c = fgetc(s);
} else {
base = 8;
}
}
} else if (base == 16) {
if (c == '0') {
c = fgetc(s);
if (c == 'x' || c == 'X') c = fgetc(s);
}
}
// Actual number parsing
for (; (c != EOF) && (d = DigitValue(c, base)) >= 0; c = fgetc(s))
v = v*base + d;
ungetc(c, s);
return minus ? -v : v;
}
double streamtofloat(FILE* s) {
int minus = 0;
int v = 0;
int d, c = 0;
int k = 1;
int w = 0;
for (c = fgetc(s);
isspace(static_cast<unsigned char>(c)) && (c != EOF);
c = fgetc(s));
// Single optional + or -
if (c == '-' || c == '+') {
minus = (c == '-');
c = fgetc(s);
}
// Actual number parsing
for (; c != EOF && (d = DigitValue(c, 10)) >= 0; c = fgetc(s))
v = v*10 + d;
if (c == '.') {
for (c = fgetc(s); c != EOF && (d = DigitValue(c, 10)) >= 0; c = fgetc(s)) {
w = w*10 + d;
k *= 10;
}
}
double f = static_cast<double>(v)
+ static_cast<double>(w) / static_cast<double>(k);
if (c == 'e' || c == 'E') {
c = fgetc(s);
int expsign = 1;
if (c == '-' || c == '+') {
expsign = (c == '-') ? -1 : 1;
c = fgetc(s);
}
int exponent = 0;
for (; (c != EOF) && (d = DigitValue(c, 10)) >= 0; c = fgetc(s)) {
exponent = exponent * 10 + d;
}
exponent *= expsign;
f *= pow(10.0, static_cast<double>(exponent));
}
ungetc(c, s);
return minus ? -f : f;
}
double strtofloat(const char* s) {
int minus = 0;
int v = 0;
int d;
int k = 1;
int w = 0;
while(*s && isspace(static_cast<unsigned char>(*s))) s++;
// Single optional + or -
if (*s == '-' || *s == '+') {
minus = (*s == '-');
s++;
}
// Actual number parsing
for (; *s && (d = DigitValue(*s, 10)) >= 0; s++)
v = v*10 + d;
if (*s == '.') {
for (++s; *s && (d = DigitValue(*s, 10)) >= 0; s++) {
w = w*10 + d;
k *= 10;
}
}
if (*s == 'e' || *s == 'E')
tprintf("WARNING: Scientific Notation not supported!");
double f = static_cast<double>(v)
+ static_cast<double>(w) / static_cast<double>(k);
return minus ? -f : f;
}
static int tvfscanf(FILE* stream, const char *format, va_list ap);
int tfscanf(FILE* stream, const char *format, ...) {
va_list ap;
int rv;
va_start(ap, format);
rv = tvfscanf(stream, format, ap);
va_end(ap);
return rv;
}
#ifdef EMBEDDED
int fscanf(FILE* stream, const char *format, ...) {
va_list ap;
int rv;
va_start(ap, format);
rv = tvfscanf(stream, format, ap);
va_end(ap);
return rv;
}
int vfscanf(FILE* stream, const char *format, ...) {
va_list ap;
int rv;
va_start(ap, format);
rv = tvfscanf(stream, format, ap);
va_end(ap);
return rv;
}
#endif
static int tvfscanf(FILE* stream, const char *format, va_list ap) {
const char *p = format;
char ch;
int q = 0;
uintmax_t val = 0;
int rank = RANK_INT; // Default rank
unsigned int width = UINT_MAX;
int base;
int flags = 0;
enum {
ST_NORMAL, // Ground state
ST_FLAGS, // Special flags
ST_WIDTH, // Field width
ST_MODIFIERS, // Length or conversion modifiers
ST_MATCH_INIT, // Initial state of %[ sequence
ST_MATCH, // Main state of %[ sequence
ST_MATCH_RANGE, // After - in a %[ sequence
} state = ST_NORMAL;
char *sarg = NULL; // %s %c or %[ string argument
enum Bail bail = BAIL_NONE;
int sign;
int converted = 0; // Successful conversions
unsigned long matchmap[((1 << CHAR_BIT)+(CHAR_BIT * sizeof(long) - 1)) /
(CHAR_BIT * sizeof(long))];
int matchinv = 0; // Is match map inverted?
unsigned char range_start = 0;
off_t start_off = ftell(stream);
// Skip leading spaces
SkipSpace(stream);
while ((ch = *p++) && !bail) {
switch (state) {
case ST_NORMAL:
if (ch == '%') {
state = ST_FLAGS;
flags = 0; rank = RANK_INT; width = UINT_MAX;
} else if (isspace(static_cast<unsigned char>(ch))) {
SkipSpace(stream);
} else {
if (fgetc(stream) != ch)
bail = BAIL_ERR; // Match failure
}
break;
case ST_FLAGS:
if (ch == '*') {
flags |= FL_SPLAT;
} else if ('0' <= ch && ch <= '9') {
width = (ch-'0');
state = ST_WIDTH;
flags |= FL_WIDTH;
} else {
state = ST_MODIFIERS;
p--; // Process this character again
}
break;
case ST_WIDTH:
if (ch >= '0' && ch <= '9') {
width = width*10+(ch-'0');
} else {
state = ST_MODIFIERS;
p--; // Process this character again
}
break;
case ST_MODIFIERS:
switch (ch) {
// Length modifiers - nonterminal sequences
case 'h':
rank--; // Shorter rank
break;
case 'l':
rank++; // Longer rank
break;
case 'j':
rank = kIntMaxRank;
break;
case 'z':
rank = kSizeTRank;
break;
case 't':
rank = kPtrDiffRank;
break;
case 'L':
case 'q':
rank = RANK_LONGLONG; // long double/long long
break;
default:
// Output modifiers - terminal sequences
state = ST_NORMAL; // Next state will be normal
if (rank < kMinRank) // Canonicalize rank
rank = kMinRank;
else if (rank > kMaxRank)
rank = kMaxRank;
switch (ch) {
case 'P': // Upper case pointer
case 'p': // Pointer
rank = RANK_PTR;
base = 0; sign = 0;
goto scan_int;
case 'i': // Base-independent integer
base = 0; sign = 1;
goto scan_int;
case 'd': // Decimal integer
base = 10; sign = 1;
goto scan_int;
case 'o': // Octal integer
base = 8; sign = 0;
goto scan_int;
case 'u': // Unsigned decimal integer
base = 10; sign = 0;
goto scan_int;
case 'x': // Hexadecimal integer
case 'X':
base = 16; sign = 0;
goto scan_int;
case 'n': // Number of characters consumed
val = ftell(stream) - start_off;
goto set_integer;
scan_int:
q = SkipSpace(stream);
if ( q <= 0 ) {
bail = BAIL_EOF;
break;
}
val = streamtoumax(stream, base);
// fall through
set_integer:
if (!(flags & FL_SPLAT)) {
converted++;
switch(rank) {
case RANK_CHAR:
*va_arg(ap, unsigned char *)
= static_cast<unsigned char>(val);
break;
case RANK_SHORT:
*va_arg(ap, unsigned short *)
= static_cast<unsigned short>(val);
break;
case RANK_INT:
*va_arg(ap, unsigned int *)
= static_cast<unsigned int>(val);
break;
case RANK_LONG:
*va_arg(ap, unsigned long *)
= static_cast<unsigned long>(val);
break;
case RANK_LONGLONG:
*va_arg(ap, unsigned long long *)
= static_cast<unsigned long long>(val);
break;
case RANK_PTR:
*va_arg(ap, void **)
= reinterpret_cast<void *>(static_cast<uintptr_t>(val));
break;
}
}
break;
case 'f': // Preliminary float value parsing
case 'g':
case 'G':
case 'e':
case 'E':
q = SkipSpace(stream);
if (q <= 0) {
bail = BAIL_EOF;
break;
}
{
double fval = streamtofloat(stream);
if (!(flags & FL_SPLAT)) {
if (rank == RANK_INT)
*va_arg(ap, float *) = static_cast<float>(fval);
else if (rank == RANK_LONG)
*va_arg(ap, double *) = static_cast<double>(fval);
converted++;
}
}
break;
case 'c': // Character
width = (flags & FL_WIDTH) ? width : 1; // Default width == 1
sarg = va_arg(ap, char *);
while (width--) {
if ((q = fgetc(stream)) <= 0) {
bail = BAIL_EOF;
break;
}
if (!(flags & FL_SPLAT)) {
*sarg++ = q;
converted++;
}
}
break;
case 's': // String
{
char *sp;
sp = sarg = va_arg(ap, char *);
while (width--) {
q = fgetc(stream);
if (isspace(static_cast<unsigned char>(q)) || q <= 0) {
ungetc(q, stream);
break;
}
if (!(flags & FL_SPLAT)) *sp = q;
sp++;
}
if (sarg == sp) {
bail = BAIL_EOF;
} else if (!(flags & FL_SPLAT)) {
*sp = '\0'; // Terminate output
converted++;
} else {
}
}
break;
case '[': // Character range
sarg = va_arg(ap, char *);
state = ST_MATCH_INIT;
matchinv = 0;
memset(matchmap, 0, sizeof matchmap);
break;
case '%': // %% sequence
if (fgetc(stream) != '%' )
bail = BAIL_ERR;
break;
default: // Anything else
bail = BAIL_ERR; // Unknown sequence
break;
}
}
break;
case ST_MATCH_INIT: // Initial state for %[ match
if (ch == '^' && !(flags & FL_INV)) {
matchinv = 1;
} else {
SetBit(matchmap, static_cast<unsigned char>(ch));
state = ST_MATCH;
}
break;
case ST_MATCH: // Main state for %[ match
if (ch == ']') {
goto match_run;
} else if (ch == '-') {
range_start = static_cast<unsigned char>(ch);
state = ST_MATCH_RANGE;
} else {
SetBit(matchmap, static_cast<unsigned char>(ch));
}
break;
case ST_MATCH_RANGE: // %[ match after -
if (ch == ']') {
SetBit(matchmap, static_cast<unsigned char>('-'));
goto match_run;
} else {
int i;
for (i = range_start ; i < (static_cast<unsigned char>(ch)) ; i++)
SetBit(matchmap, i);
state = ST_MATCH;
}
break;
match_run: // Match expression finished
char* oarg = sarg;
while (width) {
q = fgetc(stream);
unsigned char qc = static_cast<unsigned char>(q);
if (q <= 0 || !(TestBit(matchmap, qc)^matchinv)) {
ungetc(q, stream);
break;
}
if (!(flags & FL_SPLAT)) *sarg = q;
sarg++;
}
if (oarg == sarg) {
bail = (q <= 0) ? BAIL_EOF : BAIL_ERR;
} else if (!(flags & FL_SPLAT)) {
*sarg = '\0';
converted++;
}
break;
}
}
if (bail == BAIL_EOF && !converted)
converted = -1; // Return EOF (-1)
return converted;
}
#ifdef EMBEDDED
int creat(const char *pathname, mode_t mode) {
return open(pathname, O_CREAT | O_TRUNC | O_WRONLY, mode);
}
#endif // EMBEDDED
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