aiie/nix/nix-filemanager.cpp
2021-01-09 21:32:40 -05:00

285 lines
5.8 KiB
C++

#include <string.h> // strcpy
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <dirent.h>
#include <stdlib.h>
#include "nix-filemanager.h"
#define ROOTDIR "./disks/"
NixFileManager::NixFileManager()
{
numCached = 0;
}
NixFileManager::~NixFileManager()
{
}
int8_t NixFileManager::openFile(const char *name)
{
// See if there's a hole to re-use...
for (int i=0; i<numCached; i++) {
if (cachedNames[i][0] == '\0') {
strncpy(cachedNames[i], name, MAXPATH-1);
cachedNames[i][MAXPATH-1] = '\0'; // safety: ensure string terminator
fileSeekPositions[i] = 0;
return i;
}
}
// check for too many open files
if (numCached >= MAXFILES)
return -1;
// No, so we'll add it to the end
strncpy(cachedNames[numCached], name, MAXPATH-1);
cachedNames[numCached][MAXPATH-1] = '\0'; // safety: ensure string terminator
fileSeekPositions[numCached] = 0;
numCached++;
return numCached-1;
}
void NixFileManager::closeFile(int8_t fd)
{
// invalid fd provided?
if (fd < 0 || fd >= numCached)
return;
// clear the name
cachedNames[fd][0] = '\0';
}
const char *NixFileManager::fileName(int8_t fd)
{
if (fd < 0 || fd >= numCached)
return NULL;
return cachedNames[fd];
}
// FIXME make these member vars instead of globals
static DIR *dirp = NULL;
void NixFileManager::closeDir()
{
if (dirp) {
closedir(dirp);
dirp = NULL;
}
}
int16_t NixFileManager::readDir(const char *where, const char *suffix, char *outputFN, int16_t startIdx, uint16_t maxlen)
{
if (startIdx == 0 || !dirp) {
// This is an openDir() -- so reset state, open the directory, etc.
closeDir();
dirp = opendir(where);
if (!dirp)
return -1;
}
if (startIdx == 0) {
if (strcmp(where, ROOTDIR)) {
// As long as we're not at the root, we start with "../"
strcpy(outputFN, "../");
return 0;
}
}
outputFN[0] = '\0';
struct dirent *dp;
while ((dp = readdir(dirp)) != NULL) {
if (dp->d_name[0] == '.') {
// Skip any dot files (and dot directories)
continue;
}
// FIXME: skip any non-files and non-directories
if (suffix && !(dp->d_type & DT_DIR) && strlen(dp->d_name) >= 3) {
// It's a valid file. If it doesn't match any of our suffixes,
// then skip it.
char pat[40];
strncpy(pat, suffix, sizeof(pat)); // make a working copy of the suffixes
char *fsuff = &dp->d_name[strlen(dp->d_name)-3];
if (strstr(pat, ",")) {
// We have a list of suffixes. Check each of them.
bool matchesAny = false;
char *tok = strtok((char *)pat, ",");
while (tok) {
// FIXME: assumes 3 character suffixes
if (!strncasecmp(fsuff, tok, 3)) {
matchesAny = true;
break;
}
tok = strtok(NULL, ",");
}
if (!matchesAny) {
continue;
}
} else {
// One single suffix - check it
if (strcasecmp(fsuff, suffix)) {
continue;
}
}
}
// If we get here, it's something we want to show.
strncpy(outputFN, dp->d_name, maxlen-1);
if (dp->d_type & DT_DIR) {
// suffix
strcat(outputFN, "/");
}
return startIdx;
}
// Exited the loop - all done.
// didn't find any more
closeDir();
return -1;
}
void NixFileManager::getRootPath(char *toWhere, int8_t maxLen)
{
strcpy(toWhere, ROOTDIR);
// strncpy(toWhere, ROOTDIR, maxLen);
}
bool NixFileManager::setSeekPosition(int8_t fd, uint32_t pos)
{
// This could be a whole lot simpler.
bool ret = false;
FILE *f = fopen(cachedNames[fd], "r");
if (f) {
fseeko(f, 0, SEEK_END);
fileSeekPositions[fd] = ftello(f);
if (pos < ftello(f)) {
fileSeekPositions[fd] = pos;
ret = true;
}
fclose(f);
}
return ret;
};
void NixFileManager::seekToEnd(int8_t fd)
{
// This could just be a stat call...
FILE *f = fopen(cachedNames[fd], "r");
if (f) {
fseeko(f, 0, SEEK_END);
fileSeekPositions[fd] = ftello(f);
fclose(f);
}
}
int NixFileManager::write(int8_t fd, const void *buf, int nbyte)
{
if (fd < 0 || fd >= numCached) {
printf("invalid fd (out of range)\n");
return -1;
}
if (cachedNames[fd][0] == 0) {
printf("invalid fd (not opened)\n");
return -1;
}
uint32_t pos = fileSeekPositions[fd];
// open, seek, write, close.
ssize_t rv = 0;
int ffd = ::open(cachedNames[fd], O_WRONLY|O_CREAT, 0644);
if (ffd == -1) {
printf("Failed to open '%s' for writing: %d\n",
cachedNames[fd], errno);
close(ffd);
return -1;
}
if (::lseek(ffd, pos, SEEK_SET) == -1) {
printf("failed to open and seek\n");
close(ffd);
return -1;
}
rv = ::write(ffd, buf, nbyte);
if (rv != nbyte) {
printf("error writing: %d; wanted to write %d got %ld\n", errno, nbyte, rv);
}
close(ffd);
fileSeekPositions[fd]+=nbyte;
return (int)rv;
};
int NixFileManager::read(int8_t fd, void *buf, int nbyte)
{
if (fd < 0 || fd >= numCached) {
printf("no fd when reading? fd=%d\n", fd);
return -1; // FIXME: error handling?
}
if (cachedNames[fd][0] == 0) {
return -1; // FIXME: error handling?
}
off_t pos = fileSeekPositions[fd];
// open, seek, read, close.
int ffd = ::open(cachedNames[fd], O_RDONLY);
if (ffd == -1) {
return -1;
}
if (::lseek(ffd, pos, SEEK_SET) != pos) {
close(ffd);
return -1;
}
ssize_t rv = ::read(ffd, buf, nbyte);
if (rv != nbyte) {
close(ffd);
return -1;
}
fileSeekPositions[fd]+=rv;
close(ffd);
return rv;
};
int NixFileManager::lseek(int8_t fd, int offset, int whence)
{
if (whence == SEEK_CUR && offset == 0) {
return fileSeekPositions[fd];
}
if (whence == SEEK_SET) {
if (!setSeekPosition(fd, offset))
return -1;
return offset;
}
// Other cases not supported yet
return -1;
};