FSA: File of Stream Array(C/C++ Library)

I/O steps by standard C library	I/O steps by FSA	Description
#include <stdio.h> #include <fcntl.h> #include <unistd.h> int fd; fd=open(pathname,openmode); read(fd,buf,count); write(fd,buf,count); close(fd);	/* fsa.h must be included before using FSA API */ #include "fsa.h" FSA_HANDLE h; FsaOpen(&h,pathname, openmode); FsaReadStream(h,i,buf,from,count); FsaWriteStream(h,i,buf,from,count); FsaClose(&h);	It is the same as in standard C/C++ API and FSA API that the target file to be accessed must be opened at first and closed when finished. In standard C/C++, write() corresponds to FSA FsaWriteStream(),and read() to FsaReadStream(). In FSA,you need to specify starting byte position 'from' for I/O processing,because seek() is not supported. Note the important difference that,in FsaReadStream() and FsaWriteStream(),one more argument i which is the index of the target stream is specified. In FSA,I/O with different index i is completely independent and different. Also note that any stream identified by index i has its own stream size.

Standard C I/O	FSA I/O

• 0 ... success
• other ... any error detected(see fsa.h).

All data/informations are passed or received through arguments except function status.
Initial size of every streams are zero.
All function names exported by FSA begin "Fsa".
Before using any function listed bellow,fsa.h must be included in your codes(#include "fsa.h").

Major functions

n can be obtained by calling FsaGetMaxStreamCount(h,&m) where n=m-1. And,m can be extended to any number by FsaExtendMaxStreamCount(h,M). (Total count of streams will be increased at least M).

補助関数

Error handler

See how the error handler is used in the sample program tans.c.
The error handler is defined like the list bellow.

int ErrorFunc(
	/* All arguments are set by FSA */
	FSA_HANDLE  handle,       /* FSA_HANDLE currently running.   */
	const char* function,     /* FSA function name the error detected */
	int         fsa_code,     /* FSA error code(see fsa.h) that FSA function detected.
                                     (If this is FSA_ERROR_UNDEFINED,then infomations after err_no may be undefined. */
	int         err_no,       /* copy of C system's errno. Use C standard function strerror(err_no) for detail. */
	const char* msg,          /* The error message that FSA function can describe. */
	const char* source_file,  /* The source file the error occured. */
	int         source_line   /* The source line the error occured. */
	)
{
	char ch;
	printf(" FSA Error: f=%s code=%d c_er=%d msg=%s file=%s line=%d\n", function, fsa_code, err_no, msg, source_file, source_line);
	if(err_no!=0) printf("        c error=%d:%s\n",err_no,strerror(err_no));
	printf("Continue or exit (c|e)?");
	do {
		ch = toupper(getchar());
	} while (ch != 'C' && ch != 'E');
	if (ch == 'E') {
		FsaClose(&handle);
		exit(EXIT_FAILURE);
	}
	return fsa_code;
}

Sanple program (tans.c)