if {![regexp {^[0-9a-f]*$} $value]} {
			return false
		}

		return true
	}

	proc _db {args} {
		return [uplevel 1 [list ::appfs::db {*}$args]]
	}

	proc _normalizeOS {os} {
		set os [string tolower [string trim $os]]

		switch -- $os {
			"linux" - "freebsd" - "openbsd" - "netbsd" {
				return $os
			}

		return -code error "Unable to normalize CPU: $cpu"
	}

	proc init {} {
		if {[info exists ::appfs::init_called]} {
			return
		}






		set ::appfs::init_called 1

		if {![info exists ::appfs::db]} {
			file mkdir $::appfs::cachedir

			sqlite3 ::appfs::db [file join $::appfs::cachedir cache.db]
		}

		# Create tables
		_db eval {CREATE TABLE IF NOT EXISTS sites(hostname PRIMARY KEY, lastUpdate, ttl);}
		_db eval {CREATE TABLE IF NOT EXISTS packages(hostname, sha1, package, version, os, cpuArch, isLatest, haveManifest);}
		_db eval {CREATE TABLE IF NOT EXISTS files(package_sha1, type, time, source, size, perms, file_sha1, file_name, file_directory);}

		# Create indexes
		_db eval {CREATE INDEX IF NOT EXISTS sites_index ON sites (hostname);}
		_db eval {CREATE INDEX IF NOT EXISTS packages_index ON packages (hostname, package, version, os, cpuArch);}
		_db eval {CREATE INDEX IF NOT EXISTS files_index ON files (package_sha1, file_name, file_directory);}
	}

	proc download {hostname hash {method sha1}} {
		set url "http://$hostname/appfs/$method/$hash"
		set file [_cachefile $url $hash]

		if {![file exists $file]} {
			return -code error "Unable to fetch (file does not exist: $file)"
		}

		return $file
	}

	proc getindex {hostname} {
		set now [clock seconds]

		set lastUpdates [_db eval {SELECT lastUpdate, ttl FROM sites WHERE hostname = $hostname LIMIT 1;}]
		if {[llength $lastUpdates] == 0} {
			set lastUpdate 0
			set ttl 0
		} else {
			set lastUpdate [lindex $lastUpdates 0]
			set ttl [lindex $lastUpdates 1]
		}

			}
			::http::reset $token
			::http::cleanup $token
		}

		if {![info exists indexhash_data]} {
			# Cache this result for 60 seconds
			_db eval {INSERT OR REPLACE INTO sites (hostname, lastUpdate, ttl) VALUES ($hostname, $now, $::appfs::nttl);}

			return -code error "Unable to fetch $url"
		}

		set indexhash [lindex [split $indexhash_data ","] 0]

		if {![_isHash $indexhash]} {

			if {![_isHash $pkgInfo(hash)]} {
				continue
			}

			lappend curr_packages $pkgInfo(hash)

			# Do not do any additional work if we already have this package
			set existing_packages [_db eval {SELECT package FROM packages WHERE hostname = $hostname AND sha1 = $pkgInfo(hash);}]
			if {[lsearch -exact $existing_packages $pkgInfo(package)] != -1} {
				continue
			}

			if {$pkgInfo(isLatest)} {
				_db eval {UPDATE packages SET isLatest = 0 WHERE hostname = $hostname AND package = $pkgInfo($package) AND os = $pkgInfo($package) AND cpuArch = $pkgInfo(cpuArch);}
			}

			_db eval {INSERT INTO packages (hostname, sha1, package, version, os, cpuArch, isLatest, haveManifest) VALUES ($hostname, $pkgInfo(hash), $pkgInfo(package), $pkgInfo(version), $pkgInfo(os), $pkgInfo(cpuArch), $pkgInfo(isLatest), 0);}
		}

		# Look for packages that have been deleted
		set found_packages [_db eval {SELECT sha1 FROM packages WHERE hostname = $hostname;}]
		foreach package $found_packages {
			set found_packages_arr($package) 1
		}

		foreach package $curr_packages {
			unset -nocomplain found_packages_arr($package)
		}

		foreach package [array names found_packages_arr] {
			_db eval {DELETE FROM packages WHERE hostname = $hostname AND sha1 = $package;}
		}

		_db eval {INSERT OR REPLACE INTO sites (hostname, lastUpdate, ttl) VALUES ($hostname, $now, $::appfs::ttl);}

		return COMPLETE
	}

	proc getpkgmanifest {hostname package_sha1} {
		set haveManifests [_db eval {SELECT haveManifest FROM packages WHERE sha1 = $package_sha1 LIMIT 1;}]
		set haveManifest [lindex $haveManifests 0]

		if {$haveManifest} {
			return COMPLETE
		}

		if {![_isHash $package_sha1]} {
			return FAIL
		}

		set file [download $hostname $package_sha1]
		set fd [open $file]
		set pkgdata [read $fd]
		close $fd

		_db transaction {
			foreach line [split $pkgdata "\n"] {
				set line [string trim $line]

				if {$line == ""} {
					continue
				}

				}

				set fileInfo(name) [join $work ","]
				set fileInfo(name) [split [string trim $fileInfo(name) "/"] "/"]
				set fileInfo(directory) [join [lrange $fileInfo(name) 0 end-1] "/"]
				set fileInfo(name) [lindex $fileInfo(name) end]

				_db eval {INSERT INTO files (package_sha1, type, time, source, size, perms, file_sha1, file_name, file_directory) VALUES ($package_sha1, $fileInfo(type), $fileInfo(time), $fileInfo(source), $fileInfo(size), $fileInfo(perms), $fileInfo(sha1), $fileInfo(name), $fileInfo(directory) );}
				_db eval {UPDATE packages SET haveManifest = 1 WHERE sha1 = $package_sha1;}
			}
		}

		return COMPLETE
	}
}