com.norconex.commons.lang.unit.DataUnit Maven / Gradle / Ivy
/* Copyright 2010-2016 Norconex Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.norconex.commons.lang.unit;
/**
* A DataUnit represents data amounts at a given unit of
* granularity and provides utility methods to convert across units.
* A DataUnit does not maintain data amount information, but only
* helps organize and use data representations that may be maintained
* separately across various contexts. Unit values are defined as follow:
*
* - 1 B (byte) = 1 B (the smallest supported unit).
*
- 1 KB (kilobyte) = 1024 B
* - 1 MB (megabyte) = 1024 KB
* - 1 GB (gigabyte) = 1024 MB
* - 1 TB (terabyte) = 1024 GB
* - 1 PB (petabyte) = 1024 TB
*
*
* A DataUnit is mainly used to inform data-based methods
* how a given data parameter should be interpreted. For example:
*
*
* // how many kilobytes in a gigabyte amount
* long kb = DataUnit.GB.toKilobytes(3); // results = 3072
*
* // how many megabyte in a kilobyte amount
* long mb = DataUnit.KB.toMegabytes(2500); // results = 2
*
* // convert with dynamic units
* DataUnit targetUnit = // any unit
* long value = 1024;
* DataUnit kb = DataUnit.KB;
* long convertedValue = targetUnit.convert(1024, kb);
*
*
*
* @since 1.4.0
* @author Pascal Essiembre
* @see DataUnitFormatter
*/
public enum DataUnit {
/** Byte. */
B(1) {
@Override public long toBytes(long a) { return a; }
@Override public long toKilobytes(long a) { return a/(KB.a/B.a); }
@Override public long toMegabytes(long a) { return a/(MB.a/B.a); }
@Override public long toGigabytes(long a) { return a/(GB.a/B.a); }
@Override public long toTerabytes(long a) { return a/(TB.a/B.a); }
@Override public long toPetabytes(long a) { return a/(PB.a/B.a); }
@Override public long convert(long a, DataUnit u) { return u.toBytes(a); }
},
/** Kilobyte. */
KB(1024) {
@Override public long toBytes(long a) { return finer(a, B); }
@Override public long toKilobytes(long a) { return a; }
@Override public long toMegabytes(long a) { return coarser(a, MB); }
@Override public long toGigabytes(long a) { return coarser(a, GB); }
@Override public long toTerabytes(long a) { return coarser(a, TB); }
@Override public long toPetabytes(long a) { return coarser(a, PB); }
@Override public long convert(long a, DataUnit u) { return u.toKilobytes(a); }
},
/** Megabyte. */
MB(KB.a * 1024) {
@Override public long toBytes(long a) { return finer(a, B); }
@Override public long toKilobytes(long a) { return finer(a, KB); }
@Override public long toMegabytes(long a) { return a; }
@Override public long toGigabytes(long a) { return coarser(a, GB); }
@Override public long toTerabytes(long a) { return coarser(a, TB); }
@Override public long toPetabytes(long a) { return coarser(a, PB); }
@Override public long convert(long a, DataUnit u) { return u.toMegabytes(a); }
},
/** Gigabyte. */
GB(MB.a * 1024) {
@Override public long toBytes(long a) { return finer(a, B); }
@Override public long toKilobytes(long a) { return finer(a, KB); }
@Override public long toMegabytes(long a) { return finer(a, MB); }
@Override public long toGigabytes(long a) { return a; }
@Override public long toTerabytes(long a) { return coarser(a, TB); }
@Override public long toPetabytes(long a) { return coarser(a, PB); }
@Override public long convert(long a, DataUnit u) { return u.toGigabytes(a); }
},
/** Terabyte. */
TB(GB.a * 10244) {
@Override public long toBytes(long a) { return finer(a, B); }
@Override public long toKilobytes(long a) { return finer(a, KB); }
@Override public long toMegabytes(long a) { return finer(a, MB); }
@Override public long toGigabytes(long a) { return finer(a, GB); }
@Override public long toTerabytes(long a) { return a; }
@Override public long toPetabytes(long a) { return coarser(a, PB); }
@Override public long convert(long a, DataUnit u) { return u.toTerabytes(a); }
},
/** Petabyte. */
PB(TB.a * 1024) {
@Override public long toBytes(long a) { return finer(a, B); }
@Override public long toKilobytes(long a) { return finer(a, KB); }
@Override public long toMegabytes(long a) { return finer(a, MB); }
@Override public long toGigabytes(long a) { return finer(a, GB); }
@Override public long toTerabytes(long a) { return finer(a, TB); }
@Override public long toPetabytes(long a) { return a; }
@Override public long convert(long a, DataUnit u) { return u.toPetabytes(a); }
};
private static final long MAX = Long.MAX_VALUE;
private long a;
DataUnit(long byteAmount) {
this.a = byteAmount;
}
public long toBytes(long amount) {
throw new AbstractMethodError();
}
public long toKilobytes(long amount) {
throw new AbstractMethodError();
}
public long toMegabytes(long amount) {
throw new AbstractMethodError();
}
public long toGigabytes(long amount) {
throw new AbstractMethodError();
}
public long toTerabytes(long amount) {
throw new AbstractMethodError();
}
public long toPetabytes(long amount) {
throw new AbstractMethodError();
}
/**
* Converts a given source data amount and type to this type.
* @param sourceAmount source data amount
* @param sourceUnit source data unit
* @return converted value
*/
public long convert(long sourceAmount, DataUnit sourceUnit) {
throw new AbstractMethodError();
}
/*default*/ long finer(long supplied, DataUnit targetUnit) {
long m = a / targetUnit.a;
long over = MAX/m;
if (supplied > over) {
return Long.MAX_VALUE;
}
if (supplied < -over) {
return Long.MIN_VALUE;
}
return supplied * m;
}
/*default*/ long coarser(long supplied, DataUnit targetUnit) {
return supplied/(targetUnit.a/a);
}
}
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