Storage-Units

Java library for storage-/byte-units. All units defined in ISO IEC 80000-13:2008 are supported, as well as other commonly found units, like 1 Kilobyte = 1024 Byte.

Table of Contents

• Features
• Development Status
• Usage
  • Factories
  • Add, Subtract, Multiply, Divide
  • Comparison & Equality
  • Formatting
  • Conversions
  • Serialization
  • Integration
  • Compatibility
• Reference
• Alternatives
• License
• Mirrors

Features

• Immutable, type- and thread-safe object model for storage units

• Convenience factories to create units

• Basic arithmetic operators

• Comparisons and equality checks between units

• Lossless conversion between all units

• Human readable text format, including custom formats

• Compatible with any java.lang.Number

• Custom serializers for Jackson, MongoDB & EclipseLink

Available Units

Table 1. Binary units

Name	Symbol	Exponential	Absolute	Class
Byte	B	2 0 Byte	1 Byte	Byte
Kibibyte	KiB	2 10 Byte	1 024 Byte	Kibibyte
Mebibyte	MiB	2 20 Byte	1 048 576 Byte	Mebibyte
Gibibyte	GiB	2 30 Byte	1 073 741 824 Byte	Gibibyte
Tebibyte	TiB	2 40 Byte	1 099 511 627 776 Byte	Tebibyte
Pebibyte	PiB	2 50 Byte	1 125 899 906 842 624 Byte	Pebibyte
Exbibyte	EiB	2 60 Byte	1 152 921 504 606 846 976 Byte	Exbibyte
Zebibyte	ZiB	2 70 Byte	1 180 591 620 717 411 303 424 Byte	Zebibyte
Yobibyte	YiB	2 80 Byte	1 208 925 819 614 629 174 706 176 Byte	Yobibyte

Table 2. Decimal units

Name	Symbol	Exponential	Absolute	Class
Byte	B	10 0 Byte	1 Byte	Byte
Kilobyte	kB	10 3 Byte	1 000 Byte	Kilobyte
Megabyte	MB	10 6 Byte	1 000 000 Byte	Megabyte
Gigabyte	GB	10 9 Byte	1 000 000 000 Byte	Gigabyte
Terabyte	TB	10 12 Byte	1 000 000 000 000 Byte	Terabyte
Petabyte	PB	10 15 Byte	1 000 000 000 000 000 Byte	Petabyte
Exabyte	EB	10 18 Byte	1 000 000 000 000 000 000 Byte	Exabyte
Zettabyte	ZB	10 21 Byte	1 000 000 000 000 000 000 000 Byte	Zettabyte
Yottabyte	YB	10 24 Byte	1 000 000 000 000 000 000 000 000 Byte	Yottabyte

Table 3. Common units

Name	Symbol	Exponential	Absolute	Class
Byte	B	2 0 Byte	1 Byte	Byte
Kilobyte	kB	2 10 Byte	1 024 Byte	CommonKilobyte
Megabyte	MB	2 20 Byte	1 048 576 Byte	CommonMegabyte
Gigabyte	GB	2 30 Byte	1 073 741 824 Byte	CommonGigabyte
Terabyte	TB	2 40 Byte	1 099 511 627 776 Byte	CommonTerabyte
Petabyte	PB	2 50 Byte	1 125 899 906 842 624 Byte	CommonPetabyte
Exabyte	EB	2 60 Byte	1 152 921 504 606 846 976 Byte	CommonExabyte
Zettabyte	ZB	2 70 Byte	1 180 591 620 717 411 303 424 Byte	CommonZettabyte
Yottabyte	YB	2 80 Byte	1 208 925 819 614 629 174 706 176 Byte	CommonYottabyte

Development Status

All units are implemented. For future ideas, take a look at the open tickets in case you are interested.

Usage

Factories

Each unit implements a Byte-based static factory method (valueOf(BigInteger) or valueOf(long)) that can be used to represent a given number of bytes in a specific unit. Note that Long.MAX_VALUE == 8 Exabyte, thus use BigInteger if you want to work with anything bigger than a eight Exabyte. When in doubt, always use BigInteger.

// 'long' based
Kilobyte unit = Kilobyte.valueOf(500)               // 500 Byte or "0.50 kB"
Kibibyte unit = Kibibyte.valueOf(512)               // 512 Byte or "0.50 KiB"
CommonKilobyte unit = CommonKilobyte.valueOf(512)   // 512 Byte or "0.50 kB"

Megabyte unit = Megabyte.valueOf(1_000_000)             // 1 000 000 Byte or "1.00 MB"
Mebibyte unit = Mebibyte.valueOf(1_048_576)             // 1 048 576 Byte or "1.00 MiB"
CommonMegabyte unit = CommonMegabyte.valueOf(1_048_576) // 1 048 576 Byte or "1.00 MB"

// 'BigInteger' based
Kilobyte unit = Kilobyte.valueOf(BigInteger.valueOf(500))               // 500 Byte or "0.50 kB"
Kibibyte unit = Kibibyte.valueOf(BigInteger.valueOf(512))               // 512 Byte or "0.50 KiB"
CommonKilobyte unit = CommonKilobyte.valueOf(BigInteger.valueOf(512))   // 512 Byte or "0.50 KB"

Megabyte unit = Megabyte.valueOf(BigInteger.valueOf(1000000))               // 1 000 000 Byte or "1.00 MB"
Mebibyte unit = Mebibyte.valueOf(BigInteger.valueOf(1_048_576))             // 1 048 576 Byte or "1.00 MB"
CommonMegabyte unit = CommonMegabyte.valueOf(BigInteger.valueOf(1_048_576)) // 1 048 576 Byte or "1.00 MB"

The StorageUnits class offers three factory methods that automatically pick the best-matching unit for a given number of bytes.

Binary Units

// 'long' based
StorageUnit<?> unit = StorageUnits.binaryValueOf(256)       // Kibibyte (0.25 KiB)
StorageUnit<?> unit = StorageUnits.binaryValueOf(1048576)   // Mebibyte (1.00 MiB)

// 'BigInteger' based
StorageUnit<?> unit = StorageUnits.binaryValueOf(BigInteger.valueOf(256))     // Kibibyte (0.25 MiB)
StorageUnit<?> unit = StorageUnits.binaryValueOf(BigInteger.valueOf(1048576)) // Mebibyte (1.00 MiB)

Decimal Units

// 'long' based
StorageUnit<?> unit = StorageUnits.decimalValueOf(120000)    // Kilobyte (120.00 kB)
StorageUnit<?> unit = StorageUnits.decimalValueOf(1000000)   // Megabyte (1.00 MB)

// 'BigInteger' based
StorageUnit<?> unit = StorageUnits.decimalValueOf(BigInteger.valueOf(120000))    // Kilobyte (120.00 kB)
StorageUnit<?> unit = StorageUnits.decimalValueOf(BigInteger.valueOf(1000000))   // Megabyte (1.00 MB)

Common Units

// 'long' based
StorageUnit<?> unit = StorageUnits.commonValueOf(256)       // CommonKilobyte (0.25 kB)
StorageUnit<?> unit = StorageUnits.commonValueOf(1048576)   // CommonMebibyte (1.00 MB)

// 'BigInteger' based
StorageUnit<?> unit = StorageUnits.commonValueOf(BigInteger.valueOf(256))     // CommonKilobyte (0.25 kB)
StorageUnit<?> unit = StorageUnits.commonValueOf(BigInteger.valueOf(1048576)) // CommonMebibyte (1.00 MB)

Additionally high-level factory methods are also available in the StorageUnits class.

import static de.xn__ho_hia.storage_unit.StorageUnits.*;

Kibibyte unit = kibibyte(1)   // 1 024 Byte
Mebibyte unit = mebibyte(1)   // 1 048 576 Byte
Gibibyte unit = gibibyte(1)   // 1 073 741 824 Byte
Tebibyte unit = tebibyte(1)   // 1 099 511 627 776 Byte
Pebibyte unit = pebibyte(1)   // 1 125 899 906 842 624 Byte
Exbibyte unit = exbibyte(1)   // 1 152 921 504 606 846 976 Byte
Zebibyte unit = zebibyte(1)   // 1 180 591 620 717 411 303 424 Byte
Yobibyte unit = yobibyte(1)   // 1 208 925 819 614 629 174 706 176 Byte

Kilobyte unit = kilobyte(1)   // 1 000 Byte
Megabyte unit = megabyte(1)   // 1 000 000 Byte
Gigabyte unit = gigabyte(1)   // 1 000 000 000 Byte
Terabyte unit = terabyte(1)   // 1 000 000 000 000 Byte
Petabyte unit = petabyte(1)   // 1 000 000 000 000 000 Byte
Exabyte unit = exabyte(1)     // 1 000 000 000 000 000 000 Byte
Zettabyte unit = zettabyte(1) // 1 000 000 000 000 000 000 000 Byte
Yottabyte unit = yottabyte(1) // 1 000 000 000 000 000 000 000 000 Byte

CommonKilobyte unit = commonKilobyte(1)   // 1 024 Byte
CommonMegabyte unit = commonMegabyte(1)   // 1 048 576 Byte
CommonGigabyte unit = commonGigabyte(1)   // 1 073 741 824 Byte
CommonTerabyte unit = commonTerabyte(1)   // 1 099 511 627 776 Byte
CommonPetabyte unit = commonPetabyte(1)   // 1 125 899 906 842 624 Byte
CommonExabyte unit = commonExabyte(1)     // 1 152 921 504 606 846 976 Byte
CommonZettabyte unit = commonZettabyte(1) // 1 180 591 620 717 411 303 424 Byte
CommonYottabyte unit = commonYottabyte(1) // 1 208 925 819 614 629 174 706 176 Byte

Add, Subtract, Multiply, Divide

Each unit implements the basic four math operations. All operations retain their original type, e.g. [Kilobyte] + [Megabyte] = [Kilobyte]

import static de.xn__ho_hia.storage_unit.StorageUnits.*;

kilobyte(4).add(kilobyte(8))        // 4 Kilobyte + 8 Kilobyte = 12 Kilobyte = 12 000 Byte
kibibyte(1).add(1024)               // 1 Kibibyte + 1 024 Byte = 2 Kibibyte = 2 048 Byte
kibibyte(1).subtract(24)            // 1 024 Byte - 24 Byte = 1 000 Byte
megabyte(5).subtract(kilobyte(500)) // 5 Megabyte - 500 Kilobyte = 4.5 Megabyte = 4 500 Kilobyte = 4 500 000 Byte
gigabyte(1).multiply(5)             // 1 Gigabyte times 5 = 5 Gigabyte
terabyte(1).divide(5)               // 1 Terabyte divided by 5 = 0.2 Terabyte = 200 Gigabyte

Comparison & Equality

Each unit is comparable to each other unit.

import static de.xn__ho_hia.storage_unit.StorageUnits.*;

kibibyte(1024).compareTo(mebibyte(1)) == 0 // true
kibibyte(1000).compareTo(mebibyte(1)) == 0 // false
petabyte(3).compareTo(terabyte(3000)) == 0 // true

megabyte(1000).equals(gigabyte(1))         // true
megabyte(1024).equals(gigabyte(1))         // false
terabyte(12).equals(gigabyte(12000))       // true

Formatting

Each unit prints a human-readable string, representing the amount of bytes in the given unit using the symbol specified in ISO IEC 80000-13:2008.

import static de.xn__ho_hia.storage_unit.StorageUnits.*;

// default pattern '0.00'
terabyte(2).toString()                         // "2.00 TB"
gigabyte(1).add(megabyte(200)).toString()      // "1.20 GB"
petabyte(1).subtract(terabyte(250)).toString() // "0.75 PB"

// use custom pattern
kilobyte(212345).toString("0.0")                                    // "212345.0 kB"
gibibyte(2123458).asTebibyte().toString("#,###.000")                // "2,073.689 TiB"
kilobyte(120).asMegabyte().add(gigabyte(1)).toString("#,##0.00000") // "1,000.12000 MB"

// use custom pattern with specific Locale
kilobyte(212345).toString("0.0", Locale.GERMAN)                     // "212345,0 kB"
gibibyte(2123458).asTebibyte().toString("#,###.000", Locale.GERMAN) // "2.073,689 TiB"

// use custom format
Format customFormat = new DecimalFormat("#.00000");
terabyte(4).asTebibyte().toString(customFormat) // "3.63798 TiB"

// without creating unit type first
long numberOfBytes = 1_000_000_000_000_000L;
formatAsPetabyte(numberOfBytes) // "1.00 PB"
formatAsTerabyte(numberOfBytes) // "1000.00 TB"
formatAsPebibyte(numberOfBytes) // "0.89 PiB"

// use custom pattern
formatAsTerabyte(numberOfBytes, "#0.#####") // "1000 TB"
formatAsPebibyte(numberOfBytes, "#0.#####") // "0.88818 PiB"

// use custom pattern with specific Locale
formatAsTerabyte(numberOfBytes, "#0.#####", Locale.GERMAN) // "1000 TB"
formatAsPebibyte(numberOfBytes, "#0.#####", Locale.GERMAN) // "0,88818 PiB"

// use custom format
formatAsTerabyte(numberOfBytes, customFormat) // "1000.00000 TB"
formatAsPebibyte(numberOfBytes, customFormat) // ".88818 PiB"

Conversions

Each unit can be converted to each other unit without loss of information.

import static de.xn__ho_hia.storage_unit.StorageUnits.*;

Megabyte unit = kilobyte(1000).asMegabyte() // "1.00 MB"
Kilobyte unit = gigabyte(12).asKilobyte()   // "12000000.00 kB"
Gigabyte unit = terabyte(1).asGigabyte()    // "1000.00 GB"

// convert to best-match
kilobyte(1100).asBestMatchingUnit()          // "1.10 MB"
kilobyte(1100).asBestMatchingBinaryUnit()    // "1.05 MiB"
kilobyte(1100).asBestMatchingDecimalUnit()   // "1.10 MB"
kilobyte(1100).asBestMatchingCommonUnit()    // "1.05 MB"

Each unit can be expressed as a fraction of another unit (precise up to 24 decimal places)

import static de.xn__ho_hia.storage_unit.StorageUnits.*;

BigDecimal kilobytes = megabyte(1).inKilobyte()  // 1 000
BigInteger bytes = kibibyte(2).inByte()          // 2 048
BigDecimal terabytes = gigabyte(15).inTerabyte() // 0.015

Serialization

The storage-units-(eclipselink|mongodb|jackson) modules provide custom serializers to store storage units.

EclipseLink

Use any of the three converters like this:

@Entity
public class HardDisk implements Serializable {

    @Basic
    @Converter (
        name="binaryConverter",
        converterClass=de.xn__ho_hia.storage_unit.eclipselink.BinaryStorageUnitConverter.class
    )
    @Convert("binaryConverter")
    public StorageUnit<?> getFreeSize() {
        return freeSize;
    }

    @Basic
    @Converter (
        name="commonConverter",
        converterClass=de.xn__ho_hia.storage_unit.eclipselink.CommonStorageUnitConverter.class
    )
    @Convert("commonConverter")
    public StorageUnit<?> getUsedSize() {
        return usedSize;
    }

    @Basic
    @Converter (
        name="decimalConverter",
        converterClass=de.xn__ho_hia.storage_unit.eclipselink.DecimalyStorageUnitConverter.class
    )
    @Convert("decimalConverter")
    public StorageUnit<?> getTotalSize() {
        return totalSize;
    }

}

MongoDB

Use any of the three codecs like this:

CodecRegistry binaryRegistry = CodecRegistries.fromCodecs(new BinaryStorageUnitCodec(), ...);
CodecRegistry commonRegistry = CodecRegistries.fromCodecs(new CommonStorageUnitCodec(), ...);
CodecRegistry decimalRegistry = CodecRegistries.fromCodecs(new DecimalStorageUnitCodec(), ...);

Jackson

Use the provided StorageUnitModule like this:

ObjectMapper objectMapper = new ObjectMapper();
objectMapper.registerModule(new StorageUnitModule()); // defaults to binary units
objectMapper.registerModule(new StorageUnitModule(StorageUnitModule.PreferredUnitType.BINARY));
objectMapper.registerModule(new StorageUnitModule(StorageUnitModule.PreferredUnitType.COMMON));
objectMapper.registerModule(new StorageUnitModule(StorageUnitModule.PreferredUnitType.DECIMAL));

Integration

To use this project just declare the following dependency inside your POM:

<dependencies>
  <dependency>
    <groupId>de.xn--ho-hia.storage_units</groupId>
    <artifactId>storage-units</artifactId>
    <version>${version.storage-units}</version>
  </dependency>

  <!-- EclipseLink ONLY -->
  <dependency>
    <groupId>de.xn--ho-hia.storage_units</groupId>
    <artifactId>storage-units-eclipselink</artifactId>
    <version>${version.storage-units}</version>
  </dependency>
  <!-- EclipseLink ONLY -->

  <!-- MongoDB ONLY -->
  <dependency>
    <groupId>de.xn--ho-hia.storage_units</groupId>
    <artifactId>storage-units-mongodb</artifactId>
    <version>${version.storage-units}</version>
  </dependency>
  <!-- MongoDB ONLY -->

  <!-- Jackson ONLY -->
  <dependency>
    <groupId>de.xn--ho-hia.storage_units</groupId>
    <artifactId>storage-units-jackson</artifactId>
    <version>${version.storage-units}</version>
  </dependency>
  <!-- Jackson ONLY -->
</dependencies>

Replace ${version.storage-units} with the latest release. This project follows the semantic versioning guidelines.

Compatibility

This project is compatible with the following Java versions:

Table 4. Java compatibility

	1.X.Y	2.X.Y	3.X.Y	4.X.Y
Java 8	✓	✓	✓	✓
Java 7	✓

Reference

Originally inspired by Twitters util package.

Alternatives

• Byte Units

• triava

License

To the extent possible under law, the author(s) have dedicated all copyright and related and neighboring rights to this software to the public domain worldwide. This software is distributed without any warranty.

You should have received a copy of the CC0 Public Domain Dedication along with this software. If not, see http://creativecommons.org/publicdomain/zero/1.0/.

Mirrors

• https://github.com/sebhoss/storage-units

• https://bitbucket.org/sebhoss/storage-units

• https://gitlab.com/sebastian.hoss/storage-units

• http://v2.pikacode.com/sebhoss/storage-units

• http://repo.or.cz/storage-units.git