ref: b8d2bc344705ae3c530da783db45b3fefb94a5b3
dir: /src/deh_str.c/
//
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
//
// Parses Text substitution sections in dehacked files
//
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include "doomtype.h"
#include "deh_str.h"
#include "m_misc.h"
#include "z_zone.h"
typedef struct
{
char *from_text;
char *to_text;
} deh_substitution_t;
static deh_substitution_t **hash_table = NULL;
static int hash_table_entries;
static int hash_table_length = -1;
// This is the algorithm used by glib
static unsigned int strhash(const char *s)
{
const char *p = s;
unsigned int h = *p;
if (h)
{
for (p += 1; *p; p++)
h = (h << 5) - h + *p;
}
return h;
}
static deh_substitution_t *SubstitutionForString(const char *s)
{
int entry;
// Fallback if we have not initialized the hash table yet
if (hash_table_length < 0)
return NULL;
entry = strhash(s) % hash_table_length;
while (hash_table[entry] != NULL)
{
if (!strcmp(hash_table[entry]->from_text, s))
{
// substitution found!
return hash_table[entry];
}
entry = (entry + 1) % hash_table_length;
}
// no substitution found
return NULL;
}
// Look up a string to see if it has been replaced with something else
// This will be used throughout the program to substitute text
const char *DEH_String(const char *s)
{
deh_substitution_t *subst;
subst = SubstitutionForString(s);
if (subst != NULL)
{
return subst->to_text;
}
else
{
return s;
}
}
static void InitHashTable(void)
{
// init hash table
hash_table_entries = 0;
hash_table_length = 16;
hash_table = Z_Malloc(sizeof(deh_substitution_t *) * hash_table_length,
PU_STATIC, NULL);
memset(hash_table, 0, sizeof(deh_substitution_t *) * hash_table_length);
}
static void DEH_AddToHashtable(deh_substitution_t *sub);
static void IncreaseHashtable(void)
{
deh_substitution_t **old_table;
int old_table_length;
int i;
// save the old table
old_table = hash_table;
old_table_length = hash_table_length;
// double the size
hash_table_length *= 2;
hash_table = Z_Malloc(sizeof(deh_substitution_t *) * hash_table_length,
PU_STATIC, NULL);
memset(hash_table, 0, sizeof(deh_substitution_t *) * hash_table_length);
// go through the old table and insert all the old entries
for (i=0; i<old_table_length; ++i)
{
if (old_table[i] != NULL)
{
DEH_AddToHashtable(old_table[i]);
}
}
// free the old table
Z_Free(old_table);
}
static void DEH_AddToHashtable(deh_substitution_t *sub)
{
int entry;
// if the hash table is more than 60% full, increase its size
if ((hash_table_entries * 10) / hash_table_length > 6)
{
IncreaseHashtable();
}
// find where to insert it
entry = strhash(sub->from_text) % hash_table_length;
while (hash_table[entry] != NULL)
{
entry = (entry + 1) % hash_table_length;
}
hash_table[entry] = sub;
++hash_table_entries;
}
void DEH_AddStringReplacement(const char *from_text, const char *to_text)
{
deh_substitution_t *sub;
size_t len;
// Initialize the hash table if this is the first time
if (hash_table_length < 0)
{
InitHashTable();
}
// Check to see if there is an existing substitution already in place.
sub = SubstitutionForString(from_text);
if (sub != NULL)
{
Z_Free(sub->to_text);
len = strlen(to_text) + 1;
sub->to_text = Z_Malloc(len, PU_STATIC, NULL);
memcpy(sub->to_text, to_text, len);
}
else
{
// We need to allocate a new substitution.
sub = Z_Malloc(sizeof(*sub), PU_STATIC, 0);
// We need to create our own duplicates of the provided strings.
len = strlen(from_text) + 1;
sub->from_text = Z_Malloc(len, PU_STATIC, NULL);
memcpy(sub->from_text, from_text, len);
len = strlen(to_text) + 1;
sub->to_text = Z_Malloc(len, PU_STATIC, NULL);
memcpy(sub->to_text, to_text, len);
DEH_AddToHashtable(sub);
}
}
typedef enum
{
FORMAT_ARG_INVALID,
FORMAT_ARG_INT,
FORMAT_ARG_FLOAT,
FORMAT_ARG_CHAR,
FORMAT_ARG_STRING,
FORMAT_ARG_PTR,
FORMAT_ARG_SAVE_POS
} format_arg_t;
// Get the type of a format argument.
// We can mix-and-match different format arguments as long as they
// are for the same data type.
static format_arg_t FormatArgumentType(char c)
{
switch (c)
{
case 'd': case 'i': case 'o': case 'u': case 'x': case 'X':
return FORMAT_ARG_INT;
case 'e': case 'E': case 'f': case 'F': case 'g': case 'G':
case 'a': case 'A':
return FORMAT_ARG_FLOAT;
case 'c': case 'C':
return FORMAT_ARG_CHAR;
case 's': case 'S':
return FORMAT_ARG_STRING;
case 'p':
return FORMAT_ARG_PTR;
case 'n':
return FORMAT_ARG_SAVE_POS;
default:
return FORMAT_ARG_INVALID;
}
}
// Given the specified string, get the type of the first format
// string encountered.
static format_arg_t NextFormatArgument(const char **str)
{
format_arg_t argtype;
// Search for the '%' starting the next string.
while (**str != '\0')
{
if (**str == '%')
{
++*str;
// Don't stop for double-%s.
if (**str != '%')
{
break;
}
}
++*str;
}
// Find the type of the format string.
while (**str != '\0')
{
argtype = FormatArgumentType(**str);
if (argtype != FORMAT_ARG_INVALID)
{
++*str;
return argtype;
}
++*str;
}
// Stop searching, we have reached the end.
*str = NULL;
return FORMAT_ARG_INVALID;
}
// Check if the specified argument type is a valid replacement for
// the original.
static boolean ValidArgumentReplacement(format_arg_t original,
format_arg_t replacement)
{
// In general, the original and replacement types should be
// identical. However, there are some cases where the replacement
// is valid and the types don't match.
// Characters can be represented as ints.
if (original == FORMAT_ARG_CHAR && replacement == FORMAT_ARG_INT)
{
return true;
}
// Strings are pointers.
if (original == FORMAT_ARG_STRING && replacement == FORMAT_ARG_PTR)
{
return true;
}
return original == replacement;
}
// Return true if the specified string contains no format arguments.
static boolean ValidFormatReplacement(const char *original, const char *replacement)
{
const char *rover1;
const char *rover2;
int argtype1, argtype2;
// Check each argument in turn and compare types.
rover1 = original; rover2 = replacement;
for (;;)
{
argtype1 = NextFormatArgument(&rover1);
argtype2 = NextFormatArgument(&rover2);
if (argtype2 == FORMAT_ARG_INVALID)
{
// No more arguments left to read from the replacement string.
break;
}
else if (argtype1 == FORMAT_ARG_INVALID)
{
// Replacement string has more arguments than the original.
return false;
}
else if (!ValidArgumentReplacement(argtype1, argtype2))
{
// Not a valid replacement argument.
return false;
}
}
return true;
}
// Get replacement format string, checking arguments.
static const char *FormatStringReplacement(const char *s)
{
const char *repl;
repl = DEH_String(s);
if (!ValidFormatReplacement(s, repl))
{
printf("WARNING: Unsafe dehacked replacement provided for "
"printf format string: %s\n", s);
return s;
}
return repl;
}
// printf(), performing a replacement on the format string.
void DEH_printf(const char *fmt, ...)
{
va_list args;
const char *repl;
repl = FormatStringReplacement(fmt);
va_start(args, fmt);
vprintf(repl, args);
va_end(args);
}
// fprintf(), performing a replacement on the format string.
void DEH_fprintf(FILE *fstream, const char *fmt, ...)
{
va_list args;
const char *repl;
repl = FormatStringReplacement(fmt);
va_start(args, fmt);
vfprintf(fstream, repl, args);
va_end(args);
}
// snprintf(), performing a replacement on the format string.
void DEH_snprintf(char *buffer, size_t len, const char *fmt, ...)
{
va_list args;
const char *repl;
repl = FormatStringReplacement(fmt);
va_start(args, fmt);
M_vsnprintf(buffer, len, repl, args);
va_end(args);
}