/*

 *

 *

 *

 */

#include <string.h>

#include "jimage.hpp"

#include "imageFile.hpp"

/*

 * JImageOpen - Given the supplied full path file name, open an image file. This

 * function will also initialize tables and retrieve meta-data necessary to

 * satisfy other functions in the API. If the image file has been previously

 * open, a new open request will share memory and resources used by the previous

 * open. A call to JImageOpen should be balanced by a call to JImageClose, to

 * release memory and resources used. If the image file is not found or cannot

 * be open, then NULL is returned and error will contain a reason for the

 * failure; a positive value for a system error number, negative for a jimage

 * specific error (see JImage Error Codes.)

 *

 *  Ex.

 *   jint error;

 *   JImageFile* jimage = (*JImageOpen)(JAVA_HOME "lib/modules/bootmodules.jimage", &error);

 *   if (image == NULL) {

 *     tty->print_cr("JImage failed to open: %d", error);

 *     ...

 *   }

 *   ...

 */

extern "C" JImageFile* JIMAGE_Open(const char *name, jint* error) {

    // TODO - return a meaningful error code

    *error = 0;

    ImageFileReader* jfile = ImageFileReader::open(name);

    return (JImageFile*) jfile;

}

/*

 * JImageClose - Given the supplied open image file (see JImageOpen), release

 * memory and resources used by the open file and close the file. If the image

 * file is shared by other uses, release and close is deferred until the last use

 * is also closed.

 *

 * Ex.

 *  (*JImageClose)(image);

 */

extern "C" void JIMAGE_Close(JImageFile* image) {

    ImageFileReader::close((ImageFileReader*) image);

}

/*

 * JImagePackageToModule - Given an open image file (see JImageOpen) and the name

 * of a package, return the name of module where the package resides. If the

 * package does not exist in the image file, the function returns NULL.

 * The resulting string does/should not have to be released. All strings are

 * utf-8, zero byte terminated.

 *

 * Ex.

 *  const char* package = (*JImagePackageToModule)(image, "java/lang");

 *  tty->print_cr(package);

 *  —> java.base

 */

extern "C" const char* JIMAGE_PackageToModule(JImageFile* image, const char* package_name) {

    return ((ImageFileReader*) image)->get_image_module_data()->package_to_module(package_name);

}

/*

 * JImageFindResource - Given an open image file (see JImageOpen), a module

 * name, a version string and the name of a class/resource, return location

 * information describing the resource and its size. If no resource is found, the

 * function returns JIMAGE_NOT_FOUND and the value of size is undefined.

 * The version number should be "9.0" and is not used in locating the resource.

 * The resulting location does/should not have to be released.

 * All strings are utf-8, zero byte terminated.

 *

 *  Ex.

 *   jlong size;

 *   JImageLocationRef location = (*JImageFindResource)(image,

 *                                 "java.base", "9.0", "java/lang/String.class", &size);

 */

extern "C" JImageLocationRef JIMAGE_FindResource(JImageFile* image,

        const char* module_name, const char* version, const char* name,

        jlong* size) {

    // Concatenate to get full path

    char fullpath[IMAGE_MAX_PATH];

    size_t moduleNameLen = strlen(module_name);

    size_t nameLen = strlen(name);

    size_t index;

    // TBD:   assert(moduleNameLen > 0 && "module name must be non-empty");

    assert(nameLen > 0 && "name must non-empty");

    // If the concatenated string is too long for the buffer, return not found

    if (1 + moduleNameLen + 1 + nameLen + 1 > IMAGE_MAX_PATH) {

        return 0L;

    }

    index = 0;

    fullpath[index++] = '/';

    memcpy(&fullpath[index], module_name, moduleNameLen);

    index += moduleNameLen;

    fullpath[index++] = '/';

    memcpy(&fullpath[index], name, nameLen);

    index += nameLen;

    fullpath[index++] = '\0';

    JImageLocationRef loc =

            (JImageLocationRef) ((ImageFileReader*) image)->find_location_index(fullpath, (u8*) size);

    return loc;

}

/*

 * JImageGetResource - Given an open image file (see JImageOpen), a resource’s

 * location information (see JImageFindResource), a buffer of appropriate

 * size and the size, retrieve the bytes associated with the

 * resource. If the size is less than the resource size then the read is truncated.

 * If the size is greater than the resource size then the remainder of the buffer

 * is zero filled.  The function will return the actual size of the resource.

 *

 * Ex.

 *  jlong size;

 *   JImageLocationRef location = (*JImageFindResource)(image,

 *                                 "java.base", "9.0", "java/lang/String.class", &size);

 *  char* buffer = new char[size];

 *  (*JImageGetResource)(image, location, buffer, size);

 */

extern "C" jlong JIMAGE_GetResource(JImageFile* image, JImageLocationRef location,

        char* buffer, jlong size) {

    ((ImageFileReader*) image)->get_resource((u4) location, (u1*) buffer);

    return size;

}

/*

 * JImageResourceIterator - Given an open image file (see JImageOpen), a visitor

 * function and a visitor argument, iterator through each of the image's resources.

 * The visitor function is called with the image file, the module name, the

 * package name, the base name, the extension and the visitor argument. The return

 * value of the visitor function should be true, unless an early iteration exit is

 * required. All strings are utf-8, zero byte terminated.file.

 *

 * Ex.

 *   bool ctw_visitor(JImageFile* jimage, const char* module_name, const char* version,

 *                  const char* package, const char* name, const char* extension, void* arg) {

 *     if (strcmp(extension, “class”) == 0) {

 *       char path[JIMAGE_MAX_PATH];

 *       Thread* THREAD = Thread::current();

 *       jio_snprintf(path, JIMAGE_MAX_PATH - 1, "/%s/%s", package, name);

 *       ClassLoader::compile_the_world_in(path, (Handle)arg, THREAD);

 *       return !HAS_PENDING_EXCEPTION;

 *     }

 *     return true;

 *   }

 *   (*JImageResourceIterator)(image, ctw_visitor, loader);

 */

extern "C" void JIMAGE_ResourceIterator(JImageFile* image,

        JImageResourceVisitor_t visitor, void* arg) {

    ImageFileReader* imageFile = (ImageFileReader*) image;

    u4 nEntries = imageFile->table_length();

    const ImageStrings strings = imageFile->get_strings();

    for (u4 i = 0; i < nEntries; i++) {

        ImageLocation location(imageFile->get_location_data(i));

        u4 moduleOffset = (u4) location.get_attribute(ImageLocation::ATTRIBUTE_MODULE);

        if (moduleOffset == 0) {

            continue; // skip non-modules

        }

        const char *module = strings.get(moduleOffset);

        if (strcmp(module, "modules") == 0

            || strcmp(module, "packages") == 0) {

            continue; // always skip

        }

        u4 parentOffset = (u4) location.get_attribute(ImageLocation::ATTRIBUTE_PARENT);

        const char *parent = strings.get(parentOffset);

        u4 baseOffset = (u4) location.get_attribute(ImageLocation::ATTRIBUTE_BASE);

        const char *base = strings.get(baseOffset);

        u4 extOffset = (u4) location.get_attribute(ImageLocation::ATTRIBUTE_EXTENSION);

        const char *extension = strings.get(extOffset);

        if (!(*visitor)(image, module, "9", parent, base, extension, arg)) {

            break;

        }

    }

}