filemgr.cpp

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/******************************************************************************
 *
 *  filemgr.cpp -   implementation of class FileMgr used for pooling file
 *          handles
 *
 * $Id: filemgr.cpp 3819 2020-10-24 20:23:11Z scribe $
 *
 * Copyright 1998-2013 CrossWire Bible Society (http://www.crosswire.org)
 *  CrossWire Bible Society
 *  P. O. Box 2528
 *  Tempe, AZ  85280-2528
 *
 * 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 version 2.
 *
 * 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.
 *
 */

#include <filemgr.h>
#include <utilstr.h>

#include <stdlib.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <swbuf.h>
#if !defined(__GNUC__) && !defined(_WIN32_WCE)
#include <io.h>
#include <direct.h>
#else
#include <unistd.h>
#endif
#ifdef WIN32
#include <wchar.h>
#include <windows.h>
#endif


#ifndef O_BINARY
#define O_BINARY 0
#endif

#ifndef S_IRGRP
#define S_IRGRP 0
#endif

#ifndef S_IROTH
#define S_IROTH 0
#endif

// Fix for VC6
#ifndef S_IREAD
#ifdef _S_IREAD
#define S_IREAD _S_IREAD
#define S_IWRITE _S_IWRITE
#endif
#endif
// -----------

// ------- if we still don't have something
#ifndef S_IREAD
#define S_IREAD 0400
#endif
#ifndef S_IWRITE
#define S_IWRITE 0200
#endif
// -------


SWORD_NAMESPACE_START


unsigned int FileMgr::CREAT = O_CREAT;
unsigned int FileMgr::APPEND = O_APPEND;
unsigned int FileMgr::TRUNC = O_TRUNC;
unsigned int FileMgr::RDONLY = O_RDONLY;
unsigned int FileMgr::RDWR = O_RDWR;
unsigned int FileMgr::WRONLY = O_WRONLY;
unsigned int FileMgr::IREAD = S_IREAD;
unsigned int FileMgr::IWRITE = S_IWRITE;


// ---------------- statics -----------------
FileMgr *FileMgr::systemFileMgr = 0;

class __staticsystemFileMgr {
public:
    __staticsystemFileMgr() { }
    ~__staticsystemFileMgr() { delete FileMgr::systemFileMgr; }
} _staticsystemFileMgr;


FileMgr *FileMgr::getSystemFileMgr() {
    if (!systemFileMgr)
        systemFileMgr = new FileMgr();

    return systemFileMgr;
}


void FileMgr::setSystemFileMgr(FileMgr *newFileMgr) {
    if (systemFileMgr)
        delete systemFileMgr;
    systemFileMgr = newFileMgr;
}

long FileMgr::write(int fd, const void *buf, long count) {
    return ::write(fd, buf, count);
}

// --------------- end statics --------------


FileDesc::FileDesc(FileMgr *parent, const char *path, int mode, int perms, bool tryDowngrade) {
    this->parent = parent;
    this->path = 0;
    stdstr(&this->path, path);
    this->mode = mode;
    this->perms = perms;
    this->tryDowngrade = tryDowngrade;
    offset = 0;
    fd = -77;
}


FileDesc::~FileDesc() {
    if (fd > 0)
        FileMgr::closeFile(fd);

    if (path)
        delete [] path;
}


long FileDesc::seek(long offset, int whence) {
    return lseek(getFd(), offset, whence);
}


long FileDesc::read(void *buf, long count) {
    return ::read(getFd(), buf, count);
}


long FileDesc::write(const void *buf, long count) {
    return FileMgr::write(getFd(), buf, count);
}


FileMgr::FileMgr(int maxFiles) {
    this->maxFiles = maxFiles;      // must be at least 2
    files = 0;
}


FileMgr::~FileMgr() {
    FileDesc *tmp;

    while(files) {
        tmp = files->next;
        delete files;
        files = tmp;
    }
}


FileDesc *FileMgr::open(const char *path, int mode, bool tryDowngrade) {
    return open(path, mode, S_IREAD|S_IWRITE|S_IRGRP|S_IROTH, tryDowngrade);
}


FileDesc *FileMgr::open(const char *path, int mode, int perms, bool tryDowngrade) {
    FileDesc **tmp, *tmp2;

    for (tmp = &files; *tmp; tmp = &((*tmp)->next)) {
        if ((*tmp)->fd < 0)     // insert as first non-system_open file
            break;
    }

    tmp2 = new FileDesc(this, path, mode, perms, tryDowngrade);
    tmp2->next = *tmp;
    *tmp = tmp2;

    return tmp2;
}


void FileMgr::close(FileDesc *file) {
    FileDesc **loop;

    for (loop = &files; *loop; loop = &((*loop)->next)) {
        if (*loop == file) {
            *loop = (*loop)->next;
            delete file;
            break;
        }
    }
}


int FileMgr::sysOpen(FileDesc *file) {
    FileDesc **loop;
    int openCount = 1;      // because we are presently opening 1 file, and we need to be sure to close files to accomodate, if necessary

    for (loop = &files; *loop; loop = &((*loop)->next)) {

        if ((*loop)->fd > 0) {
            if (++openCount > maxFiles) {
                (*loop)->offset = lseek((*loop)->fd, 0, SEEK_CUR);
                ::close((*loop)->fd);
                (*loop)->fd = -77;
            }
        }

        if (*loop == file) {
            if (*loop != files) {
                *loop = (*loop)->next;
                file->next = files;
                files = file;
            }
            if ((hasAccess(file->path, 04)) || ((file->mode & O_CREAT) == O_CREAT)) {   // check for at least file exists / read access before we try to open
                char tries = (((file->mode & O_RDWR) == O_RDWR) && (file->tryDowngrade)) ? 2 : 1;  // try read/write if possible
                for (int i = 0; i < tries; i++) {
                    if (i > 0) {
                        file->mode = (file->mode & ~O_RDWR);    // remove write access
                        file->mode = (file->mode | O_RDONLY);// add read access
                    }
                    file->fd = openFile(file->path, file->mode|O_BINARY, file->perms);
                    if (file->fd >= 0)
                        break;
                }

                if (file->fd >= 0)
                    lseek(file->fd, file->offset, SEEK_SET);
            }
            else file->fd = -1;
            if (!*loop)
                break;
        }
    }
    return file->fd;
}


// to truncate a file at its current position
// leaving byte at current possition intact
// deleting everything afterward.
signed char FileMgr::trunc(FileDesc *file) {

    static const char *writeTest = "x";
    long size = file->seek(1, SEEK_CUR);
    if (size == 1) // was empty
        size = 0;
    char nibble [ 32767 ];
    bool writable = file->write(writeTest, 1);
    int bytes = 0;

    if (writable) {
        // get tmpfilename
        char *buf = new char [ strlen(file->path) + 10 ];
        int i;
        for (i = 0; i < 9999; i++) {
            sprintf(buf, "%stmp%.4d", file->path, i);
            if (!existsFile(buf))
                break;
        }
        if (i == 9999)
            return -2;

        FileDesc *fd = open(buf, CREAT|RDWR);
        if (!fd || fd->getFd() < 0)
            return -3;

        file->seek(0, SEEK_SET);
        while (size > 0) {
            bytes = (int)file->read(nibble, 32767);
            bytes = (bytes < size)?bytes:(int)size;
            if (fd->write(nibble, bytes) != bytes) { break; }
            size -= bytes;
        }
        if (size < 1) {
            // zero out the file
            ::close(file->fd);
            file->fd = openFile(file->path, O_TRUNC, S_IREAD|S_IWRITE|S_IRGRP|S_IROTH);
            ::close(file->fd);
            file->fd = -77; // force file open by filemgr
            // copy tmp file back (dumb, but must preserve file permissions)
            fd->seek(0, SEEK_SET);
            do {
                bytes = fd->read(nibble, 32767);
                file->write(nibble, bytes);
            } while (bytes == 32767);
        }

        close(fd);
        ::close(file->fd);
        removeFile(buf);        // remove our tmp file
        file->fd = -77; // causes file to be swapped out forcing open on next call to getFd()
    }
    else { // put offset back and return failure
        file->seek(-1, SEEK_CUR);
        return -1;
    }
    return 0;
}


SWBuf FileMgr::getEnvValue(const char *variableName) {
    return
#ifdef WIN32
        wcharToUTF8(_wgetenv((const wchar_t *)utf8ToWChar(variableName).getRawData()));
#else
        getenv(variableName);
#endif

}


bool FileMgr::hasAccess(const char *path, int mode) {
    return
#ifdef WIN32
        !_waccess((const wchar_t *)utf8ToWChar(path).getRawData(), mode);
#else
        !access(path, mode);
#endif
}


signed char FileMgr::existsFile(const char *ipath, const char *ifileName)
{
    int len = (int)strlen(ipath) + ((ifileName)?strlen(ifileName):0) + 3;
    char *ch;
    char *path = new char [ len ];
    strcpy(path, ipath);

    if ((path[strlen(path)-1] == '\\') || (path[strlen(path)-1] == '/'))
        path[strlen(path)-1] = 0;

    if (ifileName) {
        ch = path + strlen(path);
        sprintf(ch, "/%s", ifileName);
    }
    signed char retVal = hasAccess(path, 04) ? 1 : 0;
    delete [] path;
    return retVal;
}


signed char FileMgr::existsDir(const char *ipath, const char *idirName)
{
    char *ch;
    int len = (int)strlen(ipath) + ((idirName)?strlen(idirName):0) + 1;
    if (idirName)
        len +=  strlen(idirName);
    char *path = new char [ len ];
    strcpy(path, ipath);

    if ((path[strlen(path)-1] == '\\') || (path[strlen(path)-1] == '/'))
        path[strlen(path)-1] = 0;

    if (idirName) {
        ch = path + strlen(path);
        sprintf(ch, "/%s", idirName);
    }
    signed char retVal = hasAccess(path, 04) ? 1 : 0;
    delete [] path;
    return retVal;
}


std::vector<struct DirEntry> FileMgr::getDirList(const char *dirPath, bool includeSize, bool includeIsDirectory) {
    std::vector<struct DirEntry> dirList;
    SWBuf basePath = dirPath;
    if (!basePath.endsWith("/") && !basePath.endsWith("\\")) basePath += "/";

#ifndef WIN32
    DIR *dir;
    struct dirent *ent;
    if ((dir = opendir(dirPath))) {
        rewinddir(dir);
        while ((ent = readdir(dir))) {
            if ((strcmp(ent->d_name, ".")) && (strcmp(ent->d_name, ".."))) {
                struct DirEntry i;
                i.name = ent->d_name;
                if (includeIsDirectory || includeSize) i.isDirectory = FileMgr::isDirectory(basePath + ent->d_name);
                if (!i.isDirectory && includeSize) i.size = FileMgr::getFileSize(basePath + ent->d_name);
                dirList.push_back(i);
            }
        }
        closedir(dir);
    }

#else
    // Crappy Windows-specific code because well... They can't be conformant
    WIN32_FIND_DATAW fileData;
    SWBuf wcharBuf = utf8ToWChar(basePath+"*");
    const wchar_t *wcharPath = (const wchar_t *)wcharBuf.getRawData();
    HANDLE findIterator = FindFirstFileW(wcharPath, &fileData);
    if (findIterator != INVALID_HANDLE_VALUE) {
        do {
            SWBuf dirEntName = wcharToUTF8(fileData.cFileName);
            if (dirEntName != "." && dirEntName != "..") {
                struct DirEntry i;
                i.name = dirEntName;
                i.isDirectory = fileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY;
                if (!i.isDirectory && includeSize) i.size = FileMgr::getFileSize(basePath + i.name);
                dirList.push_back(i);
            }
        } while (FindNextFileW(findIterator, &fileData) != 0);
        FindClose(findIterator);
    }
#endif

    return dirList;
}


int FileMgr::createParent(const char *pName) {
    char *buf = new char [ strlen(pName) + 1 ];
    int retCode = 0;

    strcpy(buf, pName);
    int end = (int)strlen(buf) - 1;
    while (end) {
        if ((buf[end] == '/') || (buf[end] == '\\'))
            break;
        end--;
    }
    buf[end] = 0;
    if (strlen(buf)>0) {
        if (!hasAccess(buf, 02)) {  // not exists with write access?
            retCode =
#ifndef WIN32
                mkdir(buf, 0755);
#else
                _wmkdir((const wchar_t *)utf8ToWChar(buf).getRawData());
#endif
            if (retCode) {
                createParent(buf);
                retCode =
#ifndef WIN32
                    mkdir(buf, 0755);
#else
                    _wmkdir((const wchar_t *)utf8ToWChar(buf).getRawData());
#endif
            }
        }
    }
    else retCode = -1;
    delete [] buf;
    return retCode;
}


int FileMgr::openFile(const char *fName, int mode, int perms) {
    int fd =
#ifndef WIN32
        ::open(fName, mode, perms);
#else
        ::_wopen((const wchar_t *)utf8ToWChar(fName).getRawData(), mode, perms);
#endif
    return fd;
}


int FileMgr::openFileReadOnly(const char *fName) {
    return openFile(fName, O_RDONLY|O_BINARY, S_IREAD|S_IWRITE|S_IRGRP|S_IROTH);
}


int FileMgr::createPathAndFile(const char *fName) {
    int fd;

    fd = openFile(fName, O_CREAT|O_WRONLY|O_BINARY, S_IREAD|S_IWRITE|S_IRGRP|S_IROTH);
    if (fd < 1) {
        createParent(fName);
        fd = openFile(fName, O_CREAT|O_WRONLY|O_BINARY, S_IREAD|S_IWRITE|S_IRGRP|S_IROTH);
    }
    return fd;
}


void FileMgr::closeFile(int fd) {
    ::close(fd);
}


int FileMgr::copyFile(const char *sourceFile, const char *targetFile) {
    int sfd, dfd, len;
    char buf[4096];

    if ((sfd = openFile(sourceFile, O_RDONLY|O_BINARY, S_IREAD|S_IWRITE|S_IRGRP|S_IROTH)) < 1)
        return -1;
    if ((dfd = createPathAndFile(targetFile)) < 1)
        return -1;

    do {
        len = (int)read(sfd, buf, 4096);
        if (write(dfd, buf, len) != len) break;
    }
    while(len == 4096);
    ::close(dfd);
    ::close(sfd);

    return 0;
}


int FileMgr::removeFile(const char *fName) {
    return
#ifndef WIN32
    ::remove(fName);
#else
    ::_wremove((const wchar_t *)utf8ToWChar(fName).getRawData());
#endif
}


char FileMgr::getLine(FileDesc *fDesc, SWBuf &line) {
    int len = 0;
    bool more = true;
    char chunk[255];

    line = "";

    // assert we have a valid file handle
    if (fDesc->getFd() < 1)
        return 0;

    while (more) {
        more = false;
        long index = fDesc->seek(0, SEEK_CUR);
        len = (int)fDesc->read(chunk, 254);

        // assert we have a readable file (not a directory)
        if (len < 1)
            break;

        int start = 0;
        // clean up any preceding white space if we're at the beginning of line
        if (!line.length()) {
            for (;start < len; start++) {
                if ((chunk[start] != 13) && (chunk[start] != ' ') && (chunk[start] != '\t'))
                    break;
            }
        }

        // find the end
        int end;
        for (end = start; ((end < (len-1)) && (chunk[end] != 10)); end++);

        if ((chunk[end] != 10) && (len == 254)) {
            more = true;
        }
        index += (end + 1);

        // reposition to next valid place to read
        fDesc->seek(index, SEEK_SET);

        // clean up any trailing junk on line if we're at the end
        if (!more) {
            for (; end > start; end--) {
                if ((chunk[end] != 10) && (chunk[end] != 13) && (chunk[end] != ' ') && (chunk[end] != '\t')) {
                    if (chunk[end] == '\\') {
                        more = true;
                        end--;
                    }
                    break;
                }
            }
        }

        int size = (end - start) + 1;

        if (size > 0) {
            // line.appendFormatted("%.*s", size, chunk+start);
            line.append(chunk+start, size);
        }
    }
    return ((len > 0) || line.length());
}


char FileMgr::isDirectory(const char *path) {
#ifndef WIN32
    struct stat stats;
    int error = stat(path, &stats);
#else
    struct _stat stats;
    int error = _wstat((const wchar_t *)utf8ToWChar(path).getRawData(), &stats);
#endif
    if (error) return 0;
    return ((stats.st_mode & S_IFDIR) == S_IFDIR);
}


long FileMgr::getFileSize(const char *path) {
#ifndef WIN32
    struct stat stats;
    int error = stat(path, &stats);
#else
    struct _stat stats;
    int error = _wstat((const wchar_t *)utf8ToWChar(path).getRawData(), &stats);
#endif
    if (error) return 0;
    return stats.st_size;
}


int FileMgr::copyDir(const char *srcDir, const char *destDir) {
    SWBuf baseSrcPath = srcDir;
    if (!baseSrcPath.endsWith("/") && !baseSrcPath.endsWith("\\")) baseSrcPath += "/";
    SWBuf baseDestPath = destDir;
    if (!baseDestPath.endsWith("/") && !baseDestPath.endsWith("\\")) baseDestPath += "/";
    int retVal = 0;
    std::vector<DirEntry> dirList = getDirList(srcDir);
    for (unsigned int i = 0; i < dirList.size() && !retVal; ++i) {
        SWBuf srcPath  = baseSrcPath  + dirList[i].name;
        SWBuf destPath = baseDestPath + dirList[i].name;
        if (!dirList[i].isDirectory) {
            retVal = copyFile(srcPath.c_str(), destPath.c_str());
        }
        else {
            retVal = copyDir(srcPath.c_str(), destPath.c_str());
        }
    }
    return retVal;
}


int FileMgr::removeDir(const char *targetDir) {
    SWBuf basePath = targetDir;
    if (!basePath.endsWith("/") && !basePath.endsWith("\\")) basePath += "/";
    std::vector<DirEntry> dirList = getDirList(targetDir);
    for (unsigned int i = 0; i < dirList.size(); ++i) {
        SWBuf targetPath = basePath + dirList[i].name;
        if (!dirList[i].isDirectory) {
            FileMgr::removeFile(targetPath.c_str());
        }
        else {
            FileMgr::removeDir(targetPath.c_str());
        }
    }
    FileMgr::removeFile(targetDir);
    return 0;
}


void FileMgr::flush() {
    FileDesc **loop;

    for (loop = &files; *loop; loop = &((*loop)->next)) {
        if ((*loop)->fd > 0) {
            (*loop)->offset = lseek((*loop)->fd, 0, SEEK_CUR);
            ::close((*loop)->fd);
            (*loop)->fd = -77;
        }
    }
}

long FileMgr::resourceConsumption() {
    long count = 0;
    FileDesc **loop;
    for (loop = &files; *loop; loop = &((*loop)->next)) {
        if ((*loop)->fd > 0) {
            count++;
        }
    }
    return count;
}


SWBuf FileMgr::getHomeDir() {

    // figure out 'home' directory for app data
    SWBuf homeDir = getEnvValue("HOME");
    if (!homeDir.length()) {
        // silly windows
        homeDir = getEnvValue("APPDATA");
    }
    if (homeDir.length()) {
        if ((homeDir[homeDir.length()-1] != '\\') && (homeDir[homeDir.length()-1] != '/')) {
            homeDir += "/";
        }
    }

    return homeDir;
}


SWORD_NAMESPACE_END