lexlib 2.0.1

library with miscellaneous stuff
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170

// Copyright 2023 alexevier <alexevier@proton.me>
// licensed under the zlib license <https://www.zlib.net/zlib_license.html>

#if defined(__unix__)
#	define _POSIX_SOURCE
#	include<unistd.h>
#	include<fcntl.h>
#	include<sys/stat.h>
#	include<sys/mman.h>
#elif defined(_WIN32)
#	include<windows.h>
#	include<io.h>
#endif

#include<lexlib/defines.h>
#include<internal/misc.h>
#include<lexlib/cfile.h>
#include<stdio.h>

void *lexlibCFileMap(FILE *file){
#if defined(__unix__)
	int fd = fileno(file);
	if(fd == -1)
		return NULL;

	uint64_t filesize = lexlibCFileSize(file);

	int prot;
	int flag;

	int mode = fcntl(fd, F_GETFL) & O_ACCMODE;
	switch(mode){
		case O_RDONLY:
			prot = PROT_READ;
			flag = MAP_PRIVATE;
			break;
		case O_WRONLY:
			prot = PROT_WRITE;
			flag = MAP_SHARED;
			break;
		case O_RDWR:
			prot = PROT_READ | PROT_WRITE;
			flag = MAP_SHARED;
			break;
		default:
			return NULL;
	}

	void* mem = mmap(NULL, filesize, prot, flag, fd, 0);
	if(mem == MAP_FAILED)
		return NULL;

	return mem;
#elif defined(_WIN32)
	HANDLE handle = (HANDLE)_get_osfhandle(_fileno(file));
	if(handle == INVALID_HANDLE_VALUE)
		return NULL;

	DWORD flagPage;
	DWORD flagMap;

	switch(lexlibCFileMode(file) & LEXLIB_RDWR){
		case LEXLIB_RD:
			flagPage = PAGE_READONLY;
			flagMap = FILE_MAP_READ;
			break;
		case LEXLIB_WR:
			flagPage = PAGE_WRITECOPY;
			flagMap = FILE_MAP_WRITE;
			break;
		case LEXLIB_RDWR:
			flagPage = PAGE_READWRITE;
			flagMap = FILE_MAP_ALL_ACCESS;
			break;
		default:
			return NULL;
	}

	HANDLE map = CreateFileMapping(handle, NULL, flagPage, 0, 0, NULL);

	void* mem = MapViewOfFile(map, flagMap, 0, 0, 0);
	CloseHandle(map);

	return mem;
#endif
}

uint8_t lexlibCFileMode(FILE *file){
#if defined(__unix__)
	int fmode = fcntl(fileno(file), F_GETFL);
	uint8_t mode = LEXLIB_NONE;
	switch(fmode & O_ACCMODE){
		case O_RDONLY:
			mode |= LEXLIB_RD;
			break;
		case O_WRONLY:
			mode |= LEXLIB_WR;
			break;
		case O_RDWR:
			mode |= LEXLIB_RDWR;
			break;
	}

	if(!mode)
		return LEXLIB_NONE;

	if(fmode & O_CREAT)
		mode |= LEXLIB_CREATE;

	if(fmode & O_APPEND)
		mode |= LEXLIB_APPEND;

	return mode;
#elif defined(_WIN32)
	// this might not work with all libc
	if(file->_flag & 0x01)
		return LEXLIB_RD;
	if(file->_flag & 0x02)
		return LEXLIB_WR;
	if(file->_flag & 0x80)
		return LEXLIB_RDWR;
	return LEXLIB_NONE;
#endif
}

int64_t lexlibCFileSize(FILE *file){
#if defined(__unix__)
	struct stat info;
	int state = fstat(fileno(file), &info);
	if(state != 0)
		return -1;

	return (int64_t)info.st_size;
#elif defined(__WIN32)
	HANDLE handle = (HANDLE)_get_osfhandle(_fileno(file));
	if(handle == INVALID_HANDLE_VALUE)
		return -1;

	LARGE_INTEGER size;
	DWORD state = GetFileSizeEx(handle, &size);
	if(state == 0)
		return -1;

	return (int64_t)size.QuadPart;
#endif
}

uint16_t lexlibCFileType(FILE *file){
	#define RETURN(X) { fsetpos(file, &fileOffset); return X; }

	fpos_t fileOffset;
	if(fgetpos(file, &fileOffset) != 0)
		RETURN(LEXLIB_FILETYPE_UNKNOWN);
	rewind(file);

	uint8_t mem[16];
	uint16_t type = LEXLIB_FILETYPE_UNKNOWN;
	if(fread(mem, 2, 1, file) != 1)
		RETURN(LEXLIB_FILETYPE_UNKNOWN);
	type = lexlibInternalFileTypeSig(mem, 2);
	if(type){RETURN(type);}

	if(fread(mem+2, 6, 1, file) != 1)
		RETURN(LEXLIB_FILETYPE_UNKNOWN);
	type = lexlibInternalFileTypeSig(mem, 8);
	if(type){RETURN(type);}

	RETURN(LEXLIB_FILETYPE_UNKNOWN);
	#undef RETURN
}