opendrive: fill out the functionality #1026

* Add Mkdir, Rmdir, Purge, Delete, SetModTime, Copy, Move, DirMove
 * Update file size after upload
 * Add Open seek
 * Set private permission for new folder and uploaded file
 * Add docs
 * Update List function
 * Fix UserSessionInfo struct
 * Fix socket leaks
 * Don’t close resp.Body in Open method
 * Get hash when listing files

backend/opendrive/replace.go

@@ -0,0 +1,84 @@
+/*
+Translate file names for OpenDrive
+
+OpenDrive reserved characters
+
+The following characters are OpenDrive reserved characters, and can't
+be used in OpenDrive folder and file names.
+
+\\ / : * ? \" < > |"
+
+*/
+
+package opendrive
+
+import (
+	"regexp"
+	"strings"
+)
+
+// charMap holds replacements for characters
+//
+// Onedrive has a restricted set of characters compared to other cloud
+// storage systems, so we to map these to the FULLWIDTH unicode
+// equivalents
+//
+// http://unicode-search.net/unicode-namesearch.pl?term=SOLIDUS
+var (
+	charMap = map[rune]rune{
+		'\\': '＼', // FULLWIDTH REVERSE SOLIDUS
+		'*':  '＊', // FULLWIDTH ASTERISK
+		'<':  '＜', // FULLWIDTH LESS-THAN SIGN
+		'>':  '＞', // FULLWIDTH GREATER-THAN SIGN
+		'?':  '？', // FULLWIDTH QUESTION MARK
+		':':  '：', // FULLWIDTH COLON
+		'|':  '｜', // FULLWIDTH VERTICAL LINE
+		'#':  '＃', // FULLWIDTH NUMBER SIGN
+		'%':  '％', // FULLWIDTH PERCENT SIGN
+		'"':  '＂', // FULLWIDTH QUOTATION MARK - not on the list but seems to be reserved
+		'.':  '．', // FULLWIDTH FULL STOP
+		'~':  '～', // FULLWIDTH TILDE
+		' ':  '␠', // SYMBOL FOR SPACE
+	}
+	invCharMap           map[rune]rune
+	fixEndingInPeriod    = regexp.MustCompile(`\.(/|$)`)
+	fixStartingWithTilde = regexp.MustCompile(`(/|^)~`)
+	fixStartingWithSpace = regexp.MustCompile(`(/|^) `)
+)
+
+func init() {
+	// Create inverse charMap
+	invCharMap = make(map[rune]rune, len(charMap))
+	for k, v := range charMap {
+		invCharMap[v] = k
+	}
+}
+
+// replaceReservedChars takes a path and substitutes any reserved
+// characters in it
+func replaceReservedChars(in string) string {
+	// Folder names can't end with a period '.'
+	in = fixEndingInPeriod.ReplaceAllString(in, string(charMap['.'])+"$1")
+	// OneDrive for Business file or folder names cannot begin with a tilde '~'
+	in = fixStartingWithTilde.ReplaceAllString(in, "$1"+string(charMap['~']))
+	// Apparently file names can't start with space either
+	in = fixStartingWithSpace.ReplaceAllString(in, "$1"+string(charMap[' ']))
+	// Replace reserved characters
+	return strings.Map(func(c rune) rune {
+		if replacement, ok := charMap[c]; ok && c != '.' && c != '~' && c != ' ' {
+			return replacement
+		}
+		return c
+	}, in)
+}
+
+// restoreReservedChars takes a path and undoes any substitutions
+// made by replaceReservedChars
+func restoreReservedChars(in string) string {
+	return strings.Map(func(c rune) rune {
+		if replacement, ok := invCharMap[c]; ok {
+			return replacement
+		}
+		return c
+	}, in)
+}