Added PosixFile.symlink() and readLink().

src/main/cpp/generic.cpp

@@ -17,5 +17,5 @@ void mark_failed_with_code(JNIEnv *env, const char* message, int error_code, job
 
 JNIEXPORT jint JNICALL
 Java_net_rubygrapefruit_platform_internal_jni_NativeLibraryFunctions_getVersion(JNIEnv *env, jclass target) {
-    return 6;
+    return 7;
 }

src/main/cpp/posix.cpp

@@ -80,6 +80,48 @@ Java_net_rubygrapefruit_platform_internal_jni_PosixFileFunctions_stat(JNIEnv *en
     env->SetIntField(dest, modeField, 0777 & fileInfo.st_mode);
 }
 
+JNIEXPORT void JNICALL
+Java_net_rubygrapefruit_platform_internal_jni_PosixFileFunctions_symlink(JNIEnv *env, jclass target, jbyteArray path, jbyteArray contents, jobject result) {
+    jbyte* pathUtf8 = env->GetByteArrayElements(path, NULL);
+    jbyte* contentsUtf8 = env->GetByteArrayElements(contents, NULL);
+    int retval = symlink((const char*)contentsUtf8, (const char*)pathUtf8);
+    env->ReleaseByteArrayElements(path, pathUtf8, JNI_ABORT);
+    env->ReleaseByteArrayElements(contents, contentsUtf8, JNI_ABORT);
+    if (retval != 0) {
+        mark_failed_with_errno(env, "could not symlink", result);
+    }
+}
+
+JNIEXPORT jbyteArray JNICALL
+Java_net_rubygrapefruit_platform_internal_jni_PosixFileFunctions_readlink(JNIEnv *env, jclass target, jbyteArray path, jobject result) {
+    struct stat link_info;
+    jbyte* pathUtf8 = env->GetByteArrayElements(path, NULL);
+    int retval = lstat((const char*)pathUtf8, &link_info);
+    if (retval != 0) {
+        env->ReleaseByteArrayElements(path, pathUtf8, JNI_ABORT);
+        mark_failed_with_errno(env, "could not lstat file", result);
+        return NULL;
+    }
+
+    jbyteArray contents = env->NewByteArray(link_info.st_size);
+    if (contents == NULL) {
+        env->ReleaseByteArrayElements(path, pathUtf8, JNI_ABORT);
+        mark_failed_with_message(env, "could not create array", result);
+        return NULL;
+    }
+
+    jbyte* contentsUtf8 = env->GetByteArrayElements(contents, NULL);
+    retval = readlink((const char*)pathUtf8, (char*)contentsUtf8, link_info.st_size);
+    env->ReleaseByteArrayElements(path, pathUtf8, JNI_ABORT);
+    if (retval < 0) {
+        mark_failed_with_errno(env, "could not readlink", result);
+        env->ReleaseByteArrayElements(contents, contentsUtf8, JNI_ABORT);
+        return NULL;
+    }
+    env->ReleaseByteArrayElements(contents, contentsUtf8, JNI_COMMIT);
+    return contents;
+}
+
 /*
  * Process functions
  */

src/main/java/net/rubygrapefruit/platform/PosixFile.java

@@ -19,4 +19,18 @@ public interface PosixFile extends NativeIntegration {
      * @throws NativeException On failure.
      */
     int getMode(File path) throws NativeException;
+
+    /**
+     * Creates a symbolic link.
+     *
+     * @throws NativeException On failure.
+     */
+    void symlink(File link, String contents) throws NativeException;
+
+    /**
+     * Reads the contents of a symbolic link.
+     *
+     * @throws NativeException On failure.
+     */
+    String readLink(File link) throws NativeException;
 }

src/main/java/net/rubygrapefruit/platform/internal/DefaultPosixFile.java

@@ -40,12 +40,43 @@ public class DefaultPosixFile implements PosixFile {
         return stat.mode;
     }
 
+    @Override
+    public String readLink(File link) throws NativeException {
+        FunctionResult result = new FunctionResult();
+        byte[] encodedContents = PosixFileFunctions.readlink(encode(link), result);
+        if (result.isFailed()) {
+            throw new NativeException(String.format("Could not read symlink %s: %s", link, result.getMessage()));
+        }
+        return decode(encodedContents);
+    }
+
+    @Override
+    public void symlink(File link, String contents) throws NativeException {
+        FunctionResult result = new FunctionResult();
+        PosixFileFunctions.symlink(encode(link), encode(contents), result);
+        if (result.isFailed()) {
+            throw new NativeException(String.format("Could not create symlink %s: %s", link, result.getMessage()));
+        }
+    }
+
+    private String decode(byte[] path) {
+        try {
+            return new String(path, 0, path.length, characterEncoding);
+        } catch (UnsupportedEncodingException e) {
+            throw new NativeException(String.format("Could not decode path using encoding %s.", characterEncoding), e);
+        }
+    }
+
     private byte[] encode(File file) {
+        return encode(file.getPath());
+    }
+
+    private byte[] encode(String path) {
         byte[] encodedName;
         try {
-            encodedName = file.getPath().getBytes(characterEncoding);
+            encodedName = path.getBytes(characterEncoding);
         } catch (UnsupportedEncodingException e) {
-            throw new NativeException(String.format("Could not encode path for file '%s' using encoding %s.", file.getName(), characterEncoding), e);
+            throw new NativeException(String.format("Could not encode path '%s' using encoding %s.", path, characterEncoding), e);
         }
         byte[] buffer = new byte[encodedName.length + 1];
         System.arraycopy(encodedName, 0, buffer, 0, encodedName.length);

src/main/java/net/rubygrapefruit/platform/internal/jni/NativeLibraryFunctions.java

@@ -4,7 +4,7 @@ import net.rubygrapefruit.platform.internal.FunctionResult;
 import net.rubygrapefruit.platform.internal.MutableSystemInfo;
 
 public class NativeLibraryFunctions {
-    public static final int VERSION = 6;
+    public static final int VERSION = 7;
 
     public static native int getVersion();
 

src/main/java/net/rubygrapefruit/platform/internal/jni/PosixFileFunctions.java

@@ -7,4 +7,8 @@ public class PosixFileFunctions {
     public static native void chmod(byte[] file, int perms, FunctionResult result);
 
     public static native void stat(byte[] file, FileStat stat, FunctionResult result);
+
+    public static native void symlink(byte[] file, byte[] content, FunctionResult result);
+
+    public static native byte[] readlink(byte[] file, FunctionResult result);
 }