LinkDB: move to a proper file, add test coverage

Relates to #71

LinkDB
 - move to application/LinkDB.php
 - code cleanup
   - indentation
   - whitespaces
   - formatting
 - comment cleanup
   - add missing documentation
   - unify formatting

Test coverage for LinkDB
 - constructor
 - public / private access
 - link-related methods

Shaarli utilities (LinkDB dependencies)
 - move startsWith() and endsWith() functions to application/Utils.php
 - add test coverage

Dev utilities
 - Composer: add PHPUnit to dev dependencies
 - Makefile:
    - update lint targets
    - add test targets
    - generate coverage reports

Signed-off-by: VirtualTam <virtualtam@flibidi.net>

1 files changed, 45 insertions, 0 deletions

diff --git a/application/Utils.php b/application/Utils.php
new file mode 100644
index 00000000..737f1502
--- /dev/null
+++ b/application/Utils.php
@@ -0,0 +1,45 @@
+<?php
+/**
+ * Shaarli utilities
+ */
+
+/**
+ *  Returns the small hash of a string, using RFC 4648 base64url format
+ *
+ *  Small hashes:
+ *   - are unique (well, as unique as crc32, at last)
+ *   - are always 6 characters long.
+ *   - only use the following characters: a-z A-Z 0-9 - _ @
+ *   - are NOT cryptographically secure (they CAN be forged)
+ *
+ *  In Shaarli, they are used as a tinyurl-like link to individual entries,
+ *  e.g. smallHash('20111006_131924') --> yZH23w
+ */
+function smallHash($text)
+{
+    $t = rtrim(base64_encode(hash('crc32', $text, true)), '=');
+    return strtr($t, '+/', '-_');
+}
+
+/**
+ * Tells if a string start with a substring
+ */
+function startsWith($haystack, $needle, $case=true)
+{
+    if ($case) {
+        return (strcmp(substr($haystack, 0, strlen($needle)), $needle) === 0);
+    }
+    return (strcasecmp(substr($haystack, 0, strlen($needle)), $needle) === 0);
+}
+
+/**
+ * Tells if a string ends with a substring
+ */
+function endsWith($haystack, $needle, $case=true)
+{
+    if ($case) {
+        return (strcmp(substr($haystack, strlen($haystack) - strlen($needle)), $needle) === 0);
+    }
+    return (strcasecmp(substr($haystack, strlen($haystack) - strlen($needle)), $needle) === 0);
+}
+?>