//Open a file and return a pointer to the file desc struct.
EspFsFile ICACHE_FLASH_ATTR *espFsOpen(char *fileName) {
if (espFsData == NULL) {
httpd_printf("Call espFsInit first!\n");
return NULL;
}
char *p=espFsData;
char *hpos;
char namebuf[256];
EspFsHeader h;
EspFsFile *r;
//Strip initial slashes
while(fileName[0]=='/') fileName++;
//Go find that file!
while(1) {
hpos=p;
//Grab the next file header.
spi_flash_read((uint32)p, (uint32*)&h, sizeof(EspFsHeader));
if (h.magic!=ESPFS_MAGIC) {
httpd_printf("Magic mismatch. EspFS image broken.\n");
return NULL;
}
if (h.flags&FLAG_LASTFILE) {
httpd_printf("End of image.\n");
return NULL;
}
//Grab the name of the file.
p+=sizeof(EspFsHeader);
spi_flash_read((uint32)p, (uint32*)&namebuf, sizeof(namebuf));
// httpd_printf("Found file '%s'. Namelen=%x fileLenComp=%x, compr=%d flags=%d\n",
// namebuf, (unsigned int)h.nameLen, (unsigned int)h.fileLenComp, h.compression, h.flags);
if (strcmp(namebuf, fileName)==0) {
//Yay, this is the file we need!
p+=h.nameLen; //Skip to content.
r=(EspFsFile *)malloc(sizeof(EspFsFile)); //Alloc file desc mem
// httpd_printf("Alloc %p\n", r);
if (r==NULL) return NULL;
r->header=(EspFsHeader *)hpos;
r->decompressor=h.compression;
r->posComp=p;
r->posStart=p;
r->posDecomp=0;
if (h.compression==COMPRESS_NONE) {
r->decompData=NULL;
#ifdef ESPFS_HEATSHRINK
} else if (h.compression==COMPRESS_HEATSHRINK) {
//File is compressed with Heatshrink.
char parm;
heatshrink_decoder *dec;
//Decoder params are stored in 1st byte.
readFlashUnaligned(&parm, r->posComp, 1);
r->posComp++;
httpd_printf("Heatshrink compressed file; decode parms = %x\n", parm);
dec=heatshrink_decoder_alloc(16, (parm>>4)&0xf, parm&0xf);
r->decompData=dec;
#endif
} else {
// Returns flags of opened file.
int ICACHE_FLASH_ATTR espFsFlags(EspFsFile *fh) {
if (fh == NULL) {
httpd_printf("File handle not ready\n");
return -1;
}
int8_t flags;
readFlashUnaligned((char*)&flags, (char*)&fh->header->flags, 1);
return (int)flags;
}
//Read len bytes from the given file into buff. Returns the actual amount of bytes read.
int ICACHE_FLASH_ATTR espFsRead(EspFsFile *fh, char *buff, int len) {
int flen;
if (fh==NULL) return 0;
readFlashUnaligned((char*)&flen, (char*)&fh->header->fileLenComp, 4);
//Cache file length.
//Do stuff depending on the way the file is compressed.
if (fh->decompressor==COMPRESS_NONE) {
int toRead;
toRead=flen-(fh->posComp-fh->posStart);
if (len>toRead) len=toRead;
// os_printf("Reading %d bytes from %x\n", len, (unsigned int)fh->posComp);
readFlashUnaligned(buff, fh->posComp, len);
fh->posDecomp+=len;
fh->posComp+=len;
// os_printf("Done reading %d bytes, pos=%x\n", len, fh->posComp);
return len;
}
return 0;
}
