func repoParamFilename(reporoot string) (filename, reponame string, createtime time.Time, err error) {

	//
	// local filesystem repository file folder hierarchy.
	//
	// index <repo root>, cfg parameter Indexer.Path, must be relative path
	// 	  - <index>
	// reposet root
	// 	  - <index>/reposet
	// reposet kind root
	//	  - <index>/reposet/<kind>
	// reposet root folder
	// 	  - <index>/reposet/<kind>/<name>
	// reponame, composed as:
	//	  - window: uint64,    // creation time (Unix, seconds), sharding tag
	//	  - area: uint8,       // area number, sharding tag
	//	  - cat: uint8,        // category number, sharding tag
	//	  - offset: int64,     // time since creation (seconds), recovery tag
	// repo specific files and sub-folders, cfg parameters are ignored for these
	//	  - <index>/reposet/<kind>/<name>/<reponame>/corpus, cfg parameter Indexer.Corpus.Path
	//	  - <index>/reposet/<kind>/<name>/<reponame>/metadata, cfg parameter Indexer.Corpus.Metadata
	// 	  - <index>/reposet/<kind>/<name>/params, repo params file, no corresponding cfg parameter
	// 	    params file is common for all repos in a reposet
	//
	t := time.Now()	// repo create time
	o := t.Sub(t)	// seconds since repo create (zero at creation time)
	a := 0			// current area (zero ==> none)
	c := 0			// current category (zero ==> none)
	createtime = t

	window := fmt.Sprintf("w%d", t.Unix())	// seconds since Unix epoch
	area := fmt.Sprintf("-a%d", a+1)		// start at 1. 0 ==> N/A
	category := fmt.Sprintf("-c%d", c+1)	// start at 1. 0 ==> N/A
	offset := fmt.Sprintf("-o%d", o)		// 0 offset is ok

	reponame = window + area + category + offset

	filename = filepath.Join(reporoot, "params")

	return
}
// repoParamFilename returns the index repository parameters filename for a specified reposet kind root path.
repoParamFilename returns the index repository parameters filename for a specified reposet kind root path.
// repoParamFilename returns the index repository parameters filename for a specified reposet kind root path .
func repoParamFilename(reporoot string) (filename, reponame string, createtime time.Time, err error) {
	 local filesystem repository file folder hierarchy.
	 index <repo root>, cfg parameter Indexer.Path, must be relative path
	 	  - <index>
	 reposet root
	 	  - <index>/reposet
	 reposet kind root
		  - <index>/reposet/<kind>
	 reposet root folder
	 	  - <index>/reposet/<kind>/<name>
	 reponame, composed as:
		  - window: uint64,     creation time (Unix, seconds), sharding tag
		  - area: uint8,        area number, sharding tag
		  - cat: uint8,         category number, sharding tag
		  - offset: int64,      time since creation (seconds), recovery tag
	 repo specific files and sub-folders, cfg parameters are ignored for these
		  - <index>/reposet/<kind>/<name>/<reponame>/corpus, cfg parameter Indexer.Corpus.Path
		  - <index>/reposet/<kind>/<name>/<reponame>/metadata, cfg parameter Indexer.Corpus.Metadata
	 	  - <index>/reposet/<kind>/<name>/params, repo params file, no corresponding cfg parameter
	 	    params file is common for all repos in a reposet
	t := time.Now()	 repo create time
	o := t.Sub(t)	 seconds since repo create (zero at creation time)
	a := 0			 current area (zero ==> none)
	c := 0			 current category (zero ==> none)
	createtime = t
	window := fmt.Sprintf("w%d", t.Unix())	 seconds since Unix epoch
	area := fmt.Sprintf("-a%d", a+1)		 start at 1. 0 ==> N/A
	category := fmt.Sprintf("-c%d", c+1)	 start at 1. 0 ==> N/A
	offset := fmt.Sprintf("-o%d", o)		 0 offset is ok
	reponame = window + area + category + offset
	filename = filepath.Join(reporoot, "params")
	return
}
func repoParamFilename ( reporoot string ) ( filename , reponame string , createtime time . Time , err error ) { t := time . Now ( ) o := t . Sub ( t ) a := 0 c := 0 createtime = t window := fmt . Sprintf ( " " , t . Unix ( ) ) area := fmt . Sprintf ( " " , a + 1 ) category := fmt . Sprintf ( " " , c + 1 ) offset := fmt . Sprintf ( " " , o ) reponame = window + area + category + offset filename = filepath . Join ( reporoot , " " ) return }
repoParamFilename returns the index repository parameters filename for a specified reposet kind root path.
repoParamFilename returns the index repository parameters filename for a specified reposet kind root path .
// // local filesystem repository file folder hierarchy. // // index <repo root>, cfg parameter Indexer.Path, must be relative path // 	  - <index> // reposet root // 	  - <index>/reposet // reposet kind root //	  - <index>/reposet/<kind> // reposet root folder // 	  - <index>/reposet/<kind>/<name> // reponame, composed as: //	  - window: uint64,    // creation time (Unix, seconds), sharding tag //	  - area: uint8,       // area number, sharding tag //	  - cat: uint8,        // category number, sharding tag //	  - offset: int64,     // time since creation (seconds), recovery tag // repo specific files and sub-folders, cfg parameters are ignored for these //	  - <index>/reposet/<kind>/<name>/<reponame>/corpus, cfg parameter Indexer.Corpus.Path //	  - <index>/reposet/<kind>/<name>/<reponame>/metadata, cfg parameter Indexer.Corpus.Metadata // 	  - <index>/reposet/<kind>/<name>/params, repo params file, no corresponding cfg parameter // 	    params file is common for all repos in a reposet // // repo create time // seconds since repo create (zero at creation time) // current area (zero ==> none) // current category (zero ==> none) // seconds since Unix epoch // start at 1. 0 ==> N/A // start at 1. 0 ==> N/A // 0 offset is ok