dav/system.c

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2019 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>

#ifndef _WIN32
#include <unistd.h>
#endif

#include "system.h"

void sys_freedirent(SysDirEnt *ent) {
    free(ent->name);
    free(ent);
}

#ifndef _WIN32
/* ---------- POSIX implementation ---------- */

SYS_DIR sys_opendir(const char *path) {
    DIR *dir = opendir(path);
    if(!dir) {
        return NULL;
    }
    SysDir *d = malloc(sizeof(SysDir));
    d->dir = dir;
    d->ent = NULL;
    return d;
}

SysDirEnt* sys_readdir(SYS_DIR dir) {
    if(dir->ent) {
        free(dir->ent->name);
        free(dir->ent);
        dir->ent = NULL;
    }
    struct dirent *ent = readdir(dir->dir);
    if(ent) {
        SysDirEnt *e = malloc(sizeof(SysDirEnt));
        e->name = strdup(ent->d_name);
        dir->ent = e;
        return e;
    }
    return NULL;
}

void sys_closedir(SYS_DIR dir) {
    closedir(dir->dir);
    if(dir->ent) {
        free(dir->ent->name);
        free(dir->ent);
    }
    free(dir);
}

FILE* sys_fopen(const char *path, const char *mode) {
    return fopen(path, mode);
}

int sys_stat(const char *path, SYS_STAT *s) {
    return stat(path, s);
}

int sys_lstat(const char *path, SYS_STAT *s) {
    return lstat(path, s);
}

int sys_rename(const char *oldpath, const char *newpath) {
    return rename(oldpath, newpath);
}

int sys_unlink(const char *path) {
    return unlink(path);
}

int sys_mkdir(const char *path) {
    return mkdir(path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
}

ssize_t sys_readlink(const char *path, char *buffer, size_t size) {
    return readlink(path, buffer, size);
}

int sys_symlink(const char *target, const char *linkpath) {
    int err = symlink(target, linkpath);
    if(err && errno == EEXIST) {
        if(unlink(linkpath)) {
            return 1;
        }
        return sys_symlink(target, linkpath);
    }
    return err;
}

#else
/* ---------- Windows implementation ---------- */

static wchar_t* path2winpath(const char *path, int dir, int *newlen) {
    size_t len = strlen(path);
    size_t lenadd = dir ? 2 : 0;
    
    
    wchar_t *wpath = calloc(len+lenadd+1, sizeof(wchar_t));
    int wlen = MultiByteToWideChar(
            CP_UTF8,
            0,
            path,
            len,
            wpath,
            len+1
            );
    if(newlen) {
        *newlen = wlen;
    }
    for(int i=0;i<wlen;i++) {
        if(wpath[i] == L'/') {
            wpath[i] = L'\\';
        }
    }
    
    if(dir) {
        if(wpath[wlen-1] != L'\\') {
            wpath[wlen++] = L'\\';
        }
        wpath[wlen++] = L'*';
    }
    wpath[wlen] = 0;
    
    return wpath;
} 

SYS_DIR sys_opendir(const char *path) {
    struct WinDir *dir = malloc(sizeof(struct WinDir));
    wchar_t *dirpath = path2winpath(path, TRUE, NULL);
    if(!dirpath) {
        fprintf(stderr, "Cannot convert path \"%s\" to UTF16\n", path);
        free(dir);
        return NULL;
    }
    dir->first = 1;
    dir->handle = FindFirstFileW(dirpath, &dir->finddata);
    free(dirpath);
    if(dir->handle == INVALID_HANDLE_VALUE) {
        free(dir);
        return NULL;
    }
    dir->ent = NULL;
    return dir;
}

SysDirEnt* sys_readdir(SYS_DIR dir) {
    if(dir->ent) {
        free(dir->ent->name);
        free(dir->ent);
        dir->ent = NULL;
    }
    if(dir->first) {
        dir->first = 0;
    } else {
        if(FindNextFileW(dir->handle, &dir->finddata) == 0) {
            return NULL;
        }
    }
    
    size_t namelen = wcslen(dir->finddata.cFileName);
    
    char *name = malloc((namelen+1)*4);
    int nlen = WideCharToMultiByte(
            CP_UTF8,
            0,
            dir->finddata.cFileName,
            -1,
            name,
            256,
            NULL,
            NULL);
    if(nlen > 0) {
        name[nlen] = 0;
        SysDirEnt *ent = malloc(sizeof(SysDirEnt));
        ent->name = name;
        dir->ent = ent;
        return ent;
    } else {
        return NULL;
    }
}

void sys_closedir(SYS_DIR dir) {
    if(dir->ent) {
        free(dir->ent->name);
        free(dir->ent);
    }
    FindClose(dir->handle);
    free(dir);
}

FILE* sys_fopen(const char *path, const char *mode) {
    wchar_t *fpath = path2winpath(path, FALSE, NULL); 
    wchar_t *fmode = path2winpath(mode, FALSE, NULL);
    
    FILE *file = (fpath && fmode) ? _wfopen(fpath, fmode) : NULL;
    free(fpath);
    free(fmode);
    return file;
}

int sys_stat(const char *path, SYS_STAT *s) {
    wchar_t *fpath = path2winpath(path, FALSE, NULL);
    if(!fpath) {
        fprintf(stderr, "Cannot convert path \"%s\" to UTF16\n", path);
        return -1;
    }
    int ret = _wstat64(fpath, s);
    free(fpath);
    return ret;
}

int sys_lstat(const char *path, SYS_STAT *s) {
	return sys_stat(path, s); // unsupported on windows
}

int sys_rename(const char *oldpath, const char *newpath) {
    wchar_t *o = path2winpath(oldpath, FALSE, NULL);
    wchar_t *n = path2winpath(newpath, FALSE, NULL);
    if(!o || !n) {
        return -1;
    }
    
    struct __stat64 s;
    if(!_wstat64(n, &s)) {
        if(_wunlink(n)) {
            fprintf(stderr, "sys_rename: cannot delete existing file: %ls\n", n);
        }
    }
    
    int ret = _wrename(o, n);
    free(o);
    free(n);
    return ret;
}

int sys_unlink(const char *path) {
    wchar_t *wpath = path2winpath(path, FALSE, NULL);
    if(!wpath) {
        fprintf(stderr, "sys_unlink: cannot convert path\n");
        return -1;
    }
    int ret = _wunlink(wpath);
    free(wpath);
    return ret;
}

int sys_mkdir(const char *path) {
    wchar_t *wpath = path2winpath(path, FALSE, NULL);
    if(!wpath) {
        fprintf(stderr, "sys_mkdir: cannot convert path\n");
        return -1;
    }
    int ret = _wmkdir(wpath);
    free(wpath);
    return ret;
}

ssize_t sys_readlink(const char *path, char *buffer, size_t size) {
    // TODO
    fprintf(stderr, "sys_readlink: implement me\n");
    return 1;
}

int sys_symlink(const char *target, const char *linkpath) {
    // TODO
    fprintf(stderr, "sys_symlink: implement me\n");
    return 1;
}

#endif