File xvfs.c.rvt artifact 6b271a3398 part of check-in e5b6962adf

#include <xvfs-core.h>
#include <unistd.h>
#include <string.h>
#include <tcl.h>

#define XVFS_NAME_LOOKUP_ERROR (-1)
#define MIN(a, b) (((a) < (b)) ? (a) : (b))

typedef enum {
	XVFS_FILE_TYPE_REG,
	XVFS_FILE_TYPE_DIR
} xvfs_file_type_t;

typedef Tcl_WideInt xvfs_size_t;

struct xvfs_file_data {
	const char          *name;
	xvfs_file_type_t    type;
	xvfs_size_t         size;
	union {
		const unsigned char *fileContents;
		const char          **dirChildren;
	} data;
};

<?
	package require xvfs
	xvfs::main $argv
?>
static long xvfs_<?= $::xvfs::fsName ?>_nameToIndex(const char *path) {
	if (path == NULL) {
		return(XVFS_NAME_LOOKUP_ERROR);
	}

<?	for {set index 0} {$index < [llength $::xvfs::outputFiles]} {incr index} {
		set outputFile [lindex $::xvfs::outputFiles $index]
?>
	if (strcmp(path, "<?= [::xvfs::sanitizeCString $outputFile] ?>") == 0) {
		return(<?= $index ?>);
	}
<?	} ?>
	return(XVFS_NAME_LOOKUP_ERROR);
}

static const char **xvfs_<?= $::xvfs::fsName ?>_getChildren(const char *path, Tcl_WideInt *count) {
	struct xvfs_file_data *fileInfo;
	long inode;

	/*
	 * Validate input parameters
	 */
	if (count == NULL) {
		return(NULL);
	}
	
	/*
	 * Get the inode from the lookup function
	 */
	inode = xvfs_<?= $::xvfs::fsName ?>_nameToIndex(path);
	if (inode == XVFS_NAME_LOOKUP_ERROR) {
		return(NULL);
	}
	
	fileInfo = &xvfs_<?= $::xvfs::fsName ?>_data[inode];

	/*
	 * Ensure this is a directory
	 */
	if (fileInfo->type != XVFS_FILE_TYPE_DIR) {
		return(NULL);
	}
	
	*count = fileInfo->size;
	return(fileInfo->data.dirChildren);
}

static const unsigned char *xvfs_<?= $::xvfs::fsName ?>_getData(const char *path, Tcl_WideInt start, Tcl_WideInt *length) {
	struct xvfs_file_data *fileInfo;
	Tcl_WideInt resultLength;
	long inode;

	/*
	 * Validate input parameters
	 */
	if (start < 0) {
		return(NULL);
	}
	
	if (length == NULL) {
		return(NULL);
	}
	
	if (*length < 0) {
		return(NULL);
	}
	
	/*
	 * Get the inode from the lookup function
	 */
	inode = xvfs_<?= $::xvfs::fsName ?>_nameToIndex(path);
	if (inode == XVFS_NAME_LOOKUP_ERROR) {
		return(NULL);
	}
	
	fileInfo = &xvfs_<?= $::xvfs::fsName ?>_data[inode];

	/*
	 * Ensure this is a file that can be read
	 */
	if (fileInfo->type != XVFS_FILE_TYPE_REG) {
		return(NULL);
	}

	/*
	 * Validate the length
	 */
	if (start > fileInfo->size) {
		*length = -1;
		return(NULL);
	}

	if (*length == 0) {
		resultLength = fileInfo->size - start;
	} else {
		resultLength = MIN(fileInfo->size - start, *length);
	}
	*length = resultLength;
	
	/*
	 * Return the data
	 */
	return(fileInfo->data.fileContents + start);
}

int Xvfs_<?= $::xvfs::fsName ?>_Init(Tcl_Interp *interp) {
	struct Xvfs_FSInfo fsInfo = {
		.protocolVersion = XVFS_PROTOCOL_VERSION,
		.fsName          = "<?= $::xvfs::fsName ?>",
		.getChildrenProc = xvfs_<?= $::xvfs::fsName ?>_getChildren,
		.getDataProc     = xvfs_<?= $::xvfs::fsName ?>_getData
	};
	int register_ret;

#ifdef USE_TCL_STUBS
	const char *tclInitStubs_ret;
	/* Initialize Stubs */
	tclInitStubs_ret = Tcl_InitStubs(interp, TCL_PATCH_LEVEL, 0);
	if (!tclInitStubs_ret) {
		return(TCL_ERROR);
	}
#endif
	
	register_ret = Xvfs_Register(interp, &fsInfo);
	if (register_ret != TCL_OK) {
		return(register_ret);
	}
	
	return(TCL_OK);
}