Package org.graalvm.nativeimage.c.type

Class CTypeConversion

java.lang.Object

org.graalvm.nativeimage.c.type.CTypeConversion

public final class CTypeConversion
extends Object

Utility methods to convert between Java types and C types.

Since:

19.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	CTypeConversion.CCharPointerHolder	An auto-closable that holds a Java CharSequence as a null-terminated C char[] array.
static class	CTypeConversion.CCharPointerPointerHolder	An auto-closable that holds a Java CharSequence[] array as a null-terminated array of null-terminated C char[]s.

Method Summary

Modifier and Type	Method	Description
static ByteBuffer	asByteBuffer(PointerBase address, int size)	Creates a ByteBuffer that refers to the native memory at the specified address.
static boolean	toBoolean(int value)	Converts a C int containing boolean values into a Java boolean.
static boolean	toBoolean(PointerBase pointer)	Converts a C pointer into a Java boolean.
static byte	toCBoolean(boolean value)	Converts a Java boolean into a C int containing boolean values.
static CTypeConversion.CCharPointerHolder	toCBytes(byte[] bytes)	Provides access to a C pointer for the provided Java byte array.
static CTypeConversion.CCharPointerHolder	toCString(CharSequence javaString)	Provides access to a C pointer for the provided Java String, encoded with the default charset.
static UnsignedWord	toCString(CharSequence javaString, Charset charset, CCharPointer buffer, UnsignedWord bufferSize)	Copies the javaString into the buffer as a 0 terminated C string encoded with the charset character set.
static UnsignedWord	toCString(CharSequence javaString, CCharPointer buffer, UnsignedWord bufferSize)	Copies the javaString into the buffer as a 0 terminated C string encoded with the default character set.
static CTypeConversion.CCharPointerPointerHolder	toCStrings(CharSequence[] javaStrings)	Provides access to C pointers for the provided Java Strings, encoded with the default charset.
static String	toJavaString(CCharPointer cString)	Decodes a 0 terminated C char* to a Java string using the platform's default charset.
static String	toJavaString(CCharPointer cString, UnsignedWord length)	Decodes a C char* of length length to a Java string using the platform's default charset.
static String	toJavaString(CCharPointer cString, UnsignedWord length, Charset charset)	Decodes a C char* of length length to a Java string using charset.
static String	utf8ToJavaString(CCharPointer utf8String)	Decodes a UTF-8 encoded, 0 terminated C char* to a Java string.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

toCString

public static CTypeConversion.CCharPointerHolder toCString(CharSequence javaString)

Provides access to a C pointer for the provided Java String, encoded with the default charset.

Since:

19.0

toCString

public static UnsignedWord toCString(CharSequence javaString,
 CCharPointer buffer,
 UnsignedWord bufferSize)

Copies the javaString into the buffer as a 0 terminated C string encoded with the default character set.

When a nullptr is passed as the buffer and the buffer size is zero, then no copying is performed but the byte-sized length of the javaString is still returned.

In case the string is larger than the buffer, then an IllegalArgumentException is thrown.

Parameters:

javaString - managed Java string

buffer - to store the bytes of 0 terminated javaString encoded with the default charset or a nullptr

bufferSize - size of the buffer or 0 when the buffer is a nullptr

Returns:

the byte-sized length of the javaString when represented as a C string encoded with the default character set. This length does not include the 0 terminator.

Since:

19.0

toCString

public static UnsignedWord toCString(CharSequence javaString,
 Charset charset,
 CCharPointer buffer,
 UnsignedWord bufferSize)

Copies the javaString into the buffer as a 0 terminated C string encoded with the charset character set.

When a nullptr is passed as the buffer and the buffer size is zero, then no copying is performed but the byte-sized length of the javaString is still returned.

In case the string is larger than the buffer, then an IllegalArgumentException is thrown.

Parameters:

javaString - managed Java string

charset - desired character set for the returned string

buffer - to store the bytes of 0 terminated javaString encoded with charset or a nullptr

bufferSize - size of the buffer or 0 when the buffer is a nullptr

Returns:

the byte-sized length of the javaString when represented as C string encoded with the charset character set. This length does not include the 0 terminator.

Since:

19.0

toJavaString

public static String toJavaString(CCharPointer cString)

Decodes a 0 terminated C char* to a Java string using the platform's default charset.

Parameters:

cString - the pointer to a 0 terminated C string

Returns:

a Java string

Since:

19.0

toJavaString

public static String toJavaString(CCharPointer cString,
 UnsignedWord length)

Decodes a C char* of length length to a Java string using the platform's default charset.

Parameters:

cString - the pointer to a 0 terminated C string

Returns:

a Java string

Since:

19.0

toJavaString

public static String toJavaString(CCharPointer cString,
 UnsignedWord length,
 Charset charset)

Decodes a C char* of length length to a Java string using charset.

Parameters:

cString - the pointer to a 0 terminated C string

Returns:

a Java string

Since:

19.0

utf8ToJavaString

public static String utf8ToJavaString(CCharPointer utf8String)

Decodes a UTF-8 encoded, 0 terminated C char* to a Java string.

Parameters:

utf8String - the pointer to a UTF-8 encoded, 0 terminated C string

Returns:

a Java string

Since:

22.3

toCBoolean

public static byte toCBoolean(boolean value)

Converts a Java boolean into a C int containing boolean values.

Parameters:

value - the Java boolean value

Returns:

the C boolean value

Since:

19.0

toBoolean

public static boolean toBoolean(int value)

Converts a C int containing boolean values into a Java boolean.

Since:

19.0

toBoolean

public static boolean toBoolean(PointerBase pointer)

Converts a C pointer into a Java boolean.

Since:

19.0

toCStrings

public static CTypeConversion.CCharPointerPointerHolder toCStrings(CharSequence[] javaStrings)

Provides access to C pointers for the provided Java Strings, encoded with the default charset.

Since:

19.0

asByteBuffer

public static ByteBuffer asByteBuffer(PointerBase address,
 int size)

Creates a ByteBuffer that refers to the native memory at the specified address. The passed size becomes the capacity of the byte buffer, and the buffer's byte order is set to native byte order. The caller is responsible for ensuring that the memory can be safely accessed while the ByteBuffer is used, and for freeing the memory afterwards.

Since:

19.0

toCBytes

public static CTypeConversion.CCharPointerHolder toCBytes(byte[] bytes)

Provides access to a C pointer for the provided Java byte array.

Since:

22.2