package org.jruby.ext.ffi.jffi;
import java.util.Collection;
import java.util.EnumMap;
import java.util.Map;
import org.jruby.Ruby;
import org.jruby.RubyHash;
import org.jruby.RubyModule;
import org.jruby.RubyString;
import org.jruby.ext.ffi.CallbackInfo;
import org.jruby.ext.ffi.NativeType;
import org.jruby.ext.ffi.StructLayout;
import org.jruby.ext.ffi.Type;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
/**
* Some utility functions for FFI <=> jffi conversions
*/
public final class FFIUtil {
private static final com.kenai.jffi.MemoryIO IO = com.kenai.jffi.MemoryIO.getInstance();
private FFIUtil() {}
private static final Map<NativeType, com.kenai.jffi.Type> typeMap = buildTypeMap();
private static final Map<NativeType, com.kenai.jffi.Type> buildTypeMap() {
Map<NativeType, com.kenai.jffi.Type> m = new EnumMap<NativeType, com.kenai.jffi.Type>(NativeType.class);
m.put(NativeType.VOID, com.kenai.jffi.Type.VOID);
m.put(NativeType.BOOL, com.kenai.jffi.Type.UINT8);
m.put(NativeType.CHAR, com.kenai.jffi.Type.SCHAR);
m.put(NativeType.SHORT, com.kenai.jffi.Type.SSHORT);
m.put(NativeType.INT, com.kenai.jffi.Type.SINT);
m.put(NativeType.LONG, com.kenai.jffi.Type.SLONG);
m.put(NativeType.LONG_LONG, com.kenai.jffi.Type.SLONG_LONG);
m.put(NativeType.UCHAR, com.kenai.jffi.Type.UCHAR);
m.put(NativeType.USHORT, com.kenai.jffi.Type.USHORT);
m.put(NativeType.UINT, com.kenai.jffi.Type.UINT);
m.put(NativeType.ULONG, com.kenai.jffi.Type.ULONG);
m.put(NativeType.ULONG_LONG, com.kenai.jffi.Type.ULONG_LONG);
m.put(NativeType.FLOAT, com.kenai.jffi.Type.FLOAT);
m.put(NativeType.DOUBLE, com.kenai.jffi.Type.DOUBLE);
m.put(NativeType.POINTER, com.kenai.jffi.Type.POINTER);
m.put(NativeType.BUFFER_IN, com.kenai.jffi.Type.POINTER);
m.put(NativeType.BUFFER_OUT, com.kenai.jffi.Type.POINTER);
m.put(NativeType.BUFFER_INOUT, com.kenai.jffi.Type.POINTER);
m.put(NativeType.STRING, com.kenai.jffi.Type.POINTER);
return m;
}
static final com.kenai.jffi.Type getFFIType(Type type) {
if (type instanceof Type.Builtin || type instanceof CallbackInfo) {
return FFIUtil.getFFIType(type.getNativeType());
} else if (type instanceof org.jruby.ext.ffi.StructLayout) {
return FFIUtil.newStruct((org.jruby.ext.ffi.StructLayout) type);
} else if (type instanceof org.jruby.ext.ffi.StructByValue) {
return FFIUtil.newStruct(((org.jruby.ext.ffi.StructByValue) type).getStructLayout());
} else if (type instanceof org.jruby.ext.ffi.Type.Array) {
return FFIUtil.newArray((org.jruby.ext.ffi.Type.Array) type);
} else if (type instanceof org.jruby.ext.ffi.MappedType) {
return FFIUtil.getFFIType(((org.jruby.ext.ffi.MappedType) type).getRealType());
} else {
return null;
}
}
static final com.kenai.jffi.Type getFFIType(NativeType type) {
return typeMap.get(type);
}
/**
* Creates a new JFFI Struct descriptor for a StructLayout
*
* @param layout The structure layout
* @return A new Struct descriptor.
*/
static final com.kenai.jffi.Struct newStruct(org.jruby.ext.ffi.StructLayout layout) {
Collection<StructLayout.Member> structMembers = layout.getMembers();
com.kenai.jffi.Type[] fields = new com.kenai.jffi.Type[structMembers.size()];
int i = 0;
for (StructLayout.Member m : structMembers) {
com.kenai.jffi.Type fieldType;
fieldType = FFIUtil.getFFIType(m.type());
if (fieldType == null) {
throw layout.getRuntime().newTypeError("unsupported Struct field type " + m);
}
fields[i++] = fieldType;
}
return new com.kenai.jffi.Struct(fields);
}
/**
* Creates a new JFFI type descriptor for an array
*
* @param layout The structure layout
* @return A new Struct descriptor.
*/
static final com.kenai.jffi.Array newArray(org.jruby.ext.ffi.Type.Array arrayType) {
com.kenai.jffi.Type componentType = FFIUtil.getFFIType(arrayType.getComponentType());
if (componentType == null) {
throw arrayType.getRuntime().newTypeError("unsupported array element type " + arrayType.getComponentType());
}
return new com.kenai.jffi.Array(componentType, arrayType.length());
}
/**
* Reads a nul-terminated string from native memory and boxes it up in a ruby
* string.
*
* @param runtime The ruby runtime for the resulting string.
* @param address The memory address to read the string from.
* @return A ruby string.
*/
static final IRubyObject getString(Ruby runtime, long address) {
if (address == 0) {
return runtime.getNil();
}
byte[] bytes = getZeroTerminatedByteArray(address);
if (bytes.length == 0) {
return RubyString.newEmptyString(runtime);
}
RubyString s = RubyString.newStringNoCopy(runtime, bytes);
s.setTaint(true);
return s;
}
static final byte[] getZeroTerminatedByteArray(long address) {
return IO.getZeroTerminatedByteArray(address);
}
static final byte[] getZeroTerminatedByteArray(long address, int maxlen) {
return IO.getZeroTerminatedByteArray(address, maxlen);
}
static final void putZeroTerminatedByteArray(long address, byte[] bytes, int off, int len) {
IO.putByteArray(address, bytes, off, len);
IO.putByte(address + len, (byte) 0);
}
static final Type resolveType(ThreadContext context, IRubyObject obj) {
if (obj instanceof Type) {
return (Type) obj;
}
final RubyModule ffi = context.getRuntime().fastGetModule("FFI");
final IRubyObject typeDefs = ffi.fastFetchConstant("TypeDefs");
if (!(typeDefs instanceof RubyHash)) {
throw context.getRuntime().newRuntimeError("invalid or corrupted FFI::TypeDefs");
}
IRubyObject type = ((RubyHash) typeDefs).fastARef(obj);
if (type == null || type.isNil()) {
type = ffi.callMethod(context, "find_type", obj);
}
if (!(type instanceof Type)) {
throw context.getRuntime().newTypeError("Could not resolve type: " + obj);
}
return (Type) type;
}
}