From: Roland Häder <roland@mxchange.org>
Date: Mon, 4 Apr 2011 23:44:28 +0000 (+0000)
Subject: - Introduced prependStringToString() which can prepend a string to an other by
X-Git-Url: https://git.mxchange.org/?p=core.git;a=commitdiff_plain;h=c1acefd913903bb304d9e2a6bd828509ed4d55c3

- Introduced prependStringToString() which can prepend a string to an other by
  maintaining the total length. The prepended string will be truncated so the
  total length will not be exceeded.
- Some debug messages added/commented out
---

diff --git a/inc/classes/main/class_BaseFrameworkSystem.php b/inc/classes/main/class_BaseFrameworkSystem.php
index aa64808e..eed98512 100644
--- a/inc/classes/main/class_BaseFrameworkSystem.php
+++ b/inc/classes/main/class_BaseFrameworkSystem.php
@@ -1602,7 +1602,7 @@ class BaseFrameworkSystem extends stdClass implements FrameworkInterface {
 	 * @param	$hex	Hexadecimal string
 	 * @return	$dec	Decimal number
 	 */
-	public final function hex2dec ($hex) {
+	protected function hex2dec ($hex) {
 		// Convert to all lower-case
 		$hex = strtolower($hex);
 
@@ -1631,10 +1631,14 @@ class BaseFrameworkSystem extends stdClass implements FrameworkInterface {
 	 * This work is based on comment #97756 on php.net documentation page at:
 	 * <http://de.php.net/manual/en/function.hexdec.php#97756>
 	 *
-	 * @param	$dec	Decimal number, even with negative sign
+	 * @param	$dec		Decimal number, even with negative sign
+	 * @param	$maxLength	Optional maximum length of the string
 	 * @return	$hex	Hexadecimal string
 	 */
-	public final function dec2hex ($dec) {
+	protected function dec2hex ($dec, $maxLength = 0) {
+		// maxLength can be zero or devideable by 2
+		assert(($maxLength == 0) || (($maxLength % 2) == 0));
+
 		// Detect sign (negative/positive numbers)
 		$sign = '';
 		if ($dec < 0) {
@@ -1653,10 +1657,12 @@ class BaseFrameworkSystem extends stdClass implements FrameworkInterface {
 		 * We need hexadecimal strings with leading zeros if the length cannot
 		 * be divided by 2
 		 */
-		if ((strlen($hex) % 2) != 0) {
-			// Prepend a zero
+		if ($maxLength > 0) {
+			// Prepend more zeros
+			$hex = $this->prependStringToString($hex, '0', $maxLength);
+		} elseif ((strlen($hex) % 2) != 0) {
 			$hex = '0' . $hex;
-		} // END - if
+		}
 
 		// Return the hexadecimal string
 		return $sign . $hex;
@@ -1668,7 +1674,7 @@ class BaseFrameworkSystem extends stdClass implements FrameworkInterface {
 	 * @param	$asc	The ASCII string to be converted
 	 * @return	$dec	Decimal number
 	 */
-	public final function asc2dec ($asc) {
+	protected function asc2dec ($asc) {
 		// Convert it into a hexadecimal number
 		$hex = bin2hex($asc);
 
@@ -1682,10 +1688,10 @@ class BaseFrameworkSystem extends stdClass implements FrameworkInterface {
 	/**
 	 * Converts a decimal number into an ASCII string.
 	 *
-	 * @param	$dec	Decimal number
+	 * @param	$dec		Decimal number
 	 * @return	$asc	An ASCII string
 	 */
-	public final function dec2asc ($dec) {
+	protected function dec2asc ($dec) {
 		// First convert the number into a hexadecimal string
 		$hex = $this->dec2hex($dec);
 
@@ -1703,8 +1709,9 @@ class BaseFrameworkSystem extends stdClass implements FrameworkInterface {
 	 * @param	$hex	Hexadecimal string
 	 * @return	$asc	An ASCII string
 	 */
-	public final function hex2asc ($hex) {
+	protected function hex2asc ($hex) {
 		// Check for length, it must be devideable by 2
+		//* DEBUG: */ $this->debugOutput('hex='.$hex);
 		assert((strlen($hex) % 2) == 0);
 
 		// Walk the string
@@ -1720,6 +1727,41 @@ class BaseFrameworkSystem extends stdClass implements FrameworkInterface {
 		// Return the final string
 		return $asc;
 	}
+
+	/**
+	 * Prepends a given string $prepend to $str with a given total length
+	 *
+	 * @param	$str		Given original string which should be prepended
+	 * @param	$prepend	The string to prepend
+	 * @param	$length		Total length of the final string
+	 * @return	$strFinal	Final prepended string
+	 */
+	protected function prependStringToString ($str, $prepend, $length) {
+		// Set final string to original string by default
+		$strFinal = $str;
+
+		// Can it devided
+		if (strlen($str) < $length) {
+			// Difference between total length and length of original string
+			$diff = $length - strlen($str);
+
+			// Prepend the string
+			$prepend = str_repeat($prepend, ($diff / strlen($prepend) + 1));
+
+			// Make sure it will definedly fit
+			assert(strlen($prepend) >= $diff);
+
+			// Cut it a little down
+			$prepend = substr($prepend, 0, $diff);
+			//* DEBUG: */ $this->debugOutput('prepend('.strlen($prepend).')='.$prepend.',diff='.$diff.',length='.$length);
+
+			// Construct the final prepended string
+			$strFinal = $prepend . $str;
+		} // END - if
+
+		// Return it
+		return $strFinal;
+	}
 }
 
 // [EOF]