Add method to read time unit from config

Time units supported:

-milliseconds (1 ms, 2 milliseconds)
-seconds (1 s, 1 sec, 1 second, 2 seconds)
-minutes (1 m, 1 min, 1 minute, 2 minutes)
-hours (1 h, 1 hr, 1 hour, 2 hours)
-days (1 d, 1 day, 2 days)
-weeks (1 w, 1 week, 2 weeks)
-months (1 mon, 1 month, 2 months)
-years (1 y, 1 year, 2 years)

This functionality is implemented in Gerrit ConfigUtil class. Add it to
JGit so it can eventually be remove from Gerrit.

Change-Id: I2d6564ff656b6ab9424a9360624061c94fd5f413
Signed-off-by: Hugo Arès <hugo.ares@ericsson.com>

3 files changed, 124 insertions, 0 deletions

diff --git a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
index b71e48b526..c2d601eed4 100644
--- a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
+++ b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
@@ -361,6 +361,8 @@ invalidShallowObject=invalid shallow object {0}, expected commit
 invalidStageForPath=Invalid stage {0} for path {1}
 invalidTagOption=Invalid tag option: {0}
 invalidTimeout=Invalid timeout: {0}
+invalidTimeUnitValue2=Invalid time unit value: {0}.{1}={2}
+invalidTimeUnitValue3=Invalid time unit value: {0}.{1}.{2}={3}
 invalidURL=Invalid URL {0}
 invalidWildcards=Invalid wildcards {0}
 invalidRefSpec=Invalid refspec {0}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
index 7c101780a7..928cc8605a 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
@@ -419,6 +419,8 @@ public class JGitText extends TranslationBundle {
 	/***/ public String invalidStageForPath;
 	/***/ public String invalidTagOption;
 	/***/ public String invalidTimeout;
+	/***/ public String invalidTimeUnitValue2;
+	/***/ public String invalidTimeUnitValue3;
 	/***/ public String invalidURL;
 	/***/ public String invalidWildcards;
 	/***/ public String invalidRefSpec;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java
index b8eba3acc2..40829f4f6f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Config.java
@@ -58,7 +58,10 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.events.ConfigChangedEvent;
@@ -490,6 +493,123 @@ public class Config {
 	}
 
 	/**
+	 * Parse a numerical time unit, such as "1 minute", from the configuration.
+	 *
+	 * @param section
+	 *            section the key is in.
+	 * @param subsection
+	 *            subsection the key is in, or null if not in a subsection.
+	 * @param name
+	 *            the key name.
+	 * @param defaultValue
+	 *            default value to return if no value was present.
+	 * @param wantUnit
+	 *            the units of {@code defaultValue} and the return value, as
+	 *            well as the units to assume if the value does not contain an
+	 *            indication of the units.
+	 * @return the value, or {@code defaultValue} if not set, expressed in
+	 *         {@code units}.
+	 * @since 4.5
+	 */
+	public long getTimeUnit(String section, String subsection, String name,
+			long defaultValue, TimeUnit wantUnit) {
+		String valueString = getString(section, subsection, name);
+
+		if (valueString == null) {
+			return defaultValue;
+		}
+
+		String s = valueString.trim();
+		if (s.length() == 0) {
+			return defaultValue;
+		}
+
+		if (s.startsWith("-")/* negative */) { //$NON-NLS-1$
+			throw notTimeUnit(section, subsection, name, valueString);
+		}
+
+		Matcher m = Pattern.compile("^(0|[1-9][0-9]*)\\s*(.*)$") //$NON-NLS-1$
+				.matcher(valueString);
+		if (!m.matches()) {
+			return defaultValue;
+		}
+
+		String digits = m.group(1);
+		String unitName = m.group(2).trim();
+
+		TimeUnit inputUnit;
+		int inputMul;
+
+		if (unitName.isEmpty()) {
+			inputUnit = wantUnit;
+			inputMul = 1;
+
+		} else if (match(unitName, "ms", "milliseconds")) { //$NON-NLS-1$ //$NON-NLS-2$
+			inputUnit = TimeUnit.MILLISECONDS;
+			inputMul = 1;
+
+		} else if (match(unitName, "s", "sec", "second", "seconds")) { //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
+			inputUnit = TimeUnit.SECONDS;
+			inputMul = 1;
+
+		} else if (match(unitName, "m", "min", "minute", "minutes")) { //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
+			inputUnit = TimeUnit.MINUTES;
+			inputMul = 1;
+
+		} else if (match(unitName, "h", "hr", "hour", "hours")) { //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
+			inputUnit = TimeUnit.HOURS;
+			inputMul = 1;
+
+		} else if (match(unitName, "d", "day", "days")) { //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+			inputUnit = TimeUnit.DAYS;
+			inputMul = 1;
+
+		} else if (match(unitName, "w", "week", "weeks")) { //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+			inputUnit = TimeUnit.DAYS;
+			inputMul = 7;
+
+		} else if (match(unitName, "mon", "month", "months")) { //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+			inputUnit = TimeUnit.DAYS;
+			inputMul = 30;
+
+		} else if (match(unitName, "y", "year", "years")) { //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
+			inputUnit = TimeUnit.DAYS;
+			inputMul = 365;
+
+		} else {
+			throw notTimeUnit(section, subsection, name, valueString);
+		}
+
+		try {
+			return wantUnit.convert(Long.parseLong(digits) * inputMul,
+					inputUnit);
+		} catch (NumberFormatException nfe) {
+			throw notTimeUnit(section, subsection, unitName, valueString);
+		}
+	}
+
+	private static boolean match(final String a, final String... cases) {
+		for (final String b : cases) {
+			if (b != null && b.equalsIgnoreCase(a)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	private IllegalArgumentException notTimeUnit(String section,
+			String subsection, String name, String valueString) {
+		if (subsection != null) {
+			return new IllegalArgumentException(
+					MessageFormat.format(JGitText.get().invalidTimeUnitValue3,
+							section, subsection, name, valueString));
+		}
+		return new IllegalArgumentException(
+				MessageFormat.format(JGitText.get().invalidTimeUnitValue2,
+						section, name, valueString));
+	}
+
+	/**
 	 * @param section
 	 *            section to search for.
 	 * @return set of all subsections of specified section within this