aiie/filemanager.h

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3.5 KiB
C
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#ifndef __FILEMANAGER_H
#define __FILEMANAGER_H
#include <stdint.h>
#define MAXFILES 4 // how many results we can simultaneously manage
#define DIRPAGESIZE 10 // how many results in one readDir
#ifndef MAXPATH
#define MAXPATH 255
#endif
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#define FMMAGIC 'F'
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#ifndef SEEK_SET
#define SEEK_SET 0
#endif
#ifndef SEEK_CUR
#define SEEK_CUR 1
#endif
class FileManager {
public:
virtual ~FileManager() {};
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#define writeByte(fd,x) {static uint8_t c = x; write(outfd, &c, 1);}
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virtual bool SerializeFile(int8_t outfd, int8_t fd) {
writeByte(outfd, FMMAGIC);
if (fd == -1 ||
cachedNames[fd][0] == '\0') {
// No file to cache; we're done
writeByte(outfd, 0);
writeByte(outfd, FMMAGIC);
return true;
}
// have a file to cache; set a marker and continue
writeByte(outfd, 1);
int8_t l = 0;
char *p = cachedNames[fd];
while (*p) {
l++;
p++;
}
writeByte(outfd, l);
for (int i=0; i<l; i++) {
writeByte(outfd, cachedNames[fd][i]);
}
writeByte(outfd, (fileSeekPositions[fd] >> 24) & 0xFF);
writeByte(outfd, (fileSeekPositions[fd] >> 16) & 0xFF);
writeByte(outfd, (fileSeekPositions[fd] >> 8) & 0xFF);
writeByte(outfd, (fileSeekPositions[fd] ) & 0xFF);
writeByte(outfd, FMMAGIC);
return true;
}
virtual int8_t DeserializeFile(int8_t infd) {
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uint8_t b;
if (read(infd, &b, 1) != 1)
return -1;
if (b != FMMAGIC)
return -1;
if (read(infd, &b, 1) != 1)
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return -1;
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if (b == 0) {
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// No file was cached. Verify footer and we're done without error
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if (read(infd, &b, 1) != 1)
return -1;
if (b != FMMAGIC) {
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// FIXME: no way to raise this error.
return -1;
}
return -1;
}
char buf[MAXPATH];
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if (read(infd, &b, 1) != 1)
return -1;
int8_t len = b;
for (int i=0; i<len; i++) {
if (read(infd, &buf[i], 1) != 1)
return false;
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}
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buf[len] = '\0';
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int8_t ret = openFile(buf);
if (ret == -1)
return ret;
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if (read(infd, &b, 1) != 1)
return -1;
fileSeekPositions[ret] <<= 8; fileSeekPositions[ret] |= b;
if (read(infd, &b, 1) != 1)
return -1;
fileSeekPositions[ret] <<= 8; fileSeekPositions[ret] |= b;
if (read(infd, &b, 1) != 1)
return -1;
fileSeekPositions[ret] <<= 8; fileSeekPositions[ret] |= b;
if (read(infd, &b, 1) != 1)
return -1;
fileSeekPositions[ret] <<= 8; fileSeekPositions[ret] |= b;
if (read(infd, &b, 1) != 1)
return -1;
if (b != FMMAGIC)
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return -1;
return ret;
}
virtual int8_t openFile(const char *name) = 0;
virtual void closeFile(int8_t fd) = 0;
virtual const char *fileName(int8_t fd) = 0;
virtual int16_t readDir(const char *where, const char *suffix, char *outputFN, int16_t startIdx, uint16_t maxlen) = 0;
virtual void closeDir() = 0;
virtual void getRootPath(char *toWhere, int8_t maxLen) = 0;
virtual uint32_t getSeekPosition(int8_t fd) {
return fileSeekPositions[fd];
};
virtual bool setSeekPosition(int8_t fd, uint32_t pos) = 0;
virtual void seekToEnd(int8_t fd) = 0;
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virtual int write(int8_t fd, const void *buf, int nbyte) = 0;
virtual int read(int8_t fd, void *buf, int nbyte) = 0;
virtual int lseek(int8_t fd, int offset, int whence) = 0;
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protected:
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volatile unsigned long fileSeekPositions[MAXFILES];
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char cachedNames[MAXFILES][MAXPATH];
};
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#undef writeByte
#endif