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src/share/vm/classfile/imageFile.cpp
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@@ -1,7 +1,7 @@
/*
- * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
@@ -21,266 +21,526 @@
* questions.
*
*/
#include "precompiled.hpp"
+#include "classfile/imageDecompressor.hpp"
#include "classfile/imageFile.hpp"
+#include "memory/resourceArea.hpp"
+#include "runtime/mutex.hpp"
+#include "runtime/mutexLocker.hpp"
#include "runtime/os.inline.hpp"
-#include "utilities/bytes.hpp"
+#include "utilities/endian.hpp"
+#include "utilities/growableArray.hpp"
-
-// Compute the Perfect Hashing hash code for the supplied string.
-u4 ImageStrings::hash_code(const char* string, u4 seed) {
+// Image files are an alternate file format for storing classes and resources. The
+// goal is to supply file access which is faster and smaller than the jar format.
+//
+// (More detailed nodes in the header.)
+//
+
+// Compute the Perfect Hashing hash code for the supplied UTF-8 string.
+s4 ImageStrings::hash_code(const char* string, s4 seed) {
+ // Access bytes as unsigned.
u1* bytes = (u1*)string;
-
// Compute hash code.
for (u1 byte = *bytes++; byte; byte = *bytes++) {
seed = (seed * HASH_MULTIPLIER) ^ byte;
}
-
- // Ensure the result is unsigned.
+ // Ensure the result is not signed.
return seed & 0x7FFFFFFF;
}
-// Test to see if string begins with start. If so returns remaining portion
-// of string. Otherwise, NULL.
+// Match up a string in a perfect hash table. Result still needs validation
+// for precise match (false positive.)
+s4 ImageStrings::find(Endian* endian, const char* name, s4* redirect, u4 length) {
+ // If the table is empty, then short cut.
+ if (redirect == NULL || length == 0) {
+ return NOT_FOUND;
+ }
+ // Compute the basic perfect hash for name.
+ s4 hash_code = ImageStrings::hash_code(name);
+ // Modulo table size.
+ s4 index = hash_code % length;
+ // Get redirect entry.
+ // value == 0 then not found
+ // value < 0 then -1 - value is true index
+ // value > 0 then value is seed for recomputing hash.
+ s4 value = endian->get(redirect[index]);
+ // if recompute is required.
+ if (value > 0) {
+ // Entry collision value, need to recompute hash.
+ hash_code = ImageStrings::hash_code(name, value);
+ // Modulo table size.
+ return hash_code % length;
+ } else if (value < 0) {
+ // Compute direct index.
+ return -1 - value;
+ }
+ // No entry found.
+ return NOT_FOUND;
+}
+
+// Test to see if UTF-8 string begins with the start UTF-8 string. If so,
+// return non-NULL address of remaining portion of string. Otherwise, return
+// NULL. Used to test sections of a path without copying from image string
+// table.
const char* ImageStrings::starts_with(const char* string, const char* start) {
char ch1, ch2;
-
// Match up the strings the best we can.
while ((ch1 = *string) && (ch2 = *start)) {
if (ch1 != ch2) {
// Mismatch, return NULL.
return NULL;
}
-
+ // Next characters.
string++, start++;
}
-
// Return remainder of string.
return string;
}
-ImageLocation::ImageLocation(u1* data) {
+// Inflates the attribute stream into individual values stored in the long
+// array _attributes. This allows an attribute value to be quickly accessed by
+// direct indexing. Unspecified values default to zero (from constructor.)
+void ImageLocation::set_data(u1* data) {
// Deflate the attribute stream into an array of attributes.
- memset(_attributes, 0, sizeof(_attributes));
u1 byte;
-
- while ((byte = *data) != ATTRIBUTE_END) {
+ // Repeat until end header is found.
+ while ((byte = *data)) {
+ // Extract kind from header byte.
u1 kind = attribute_kind(byte);
+ guarantee(kind < ATTRIBUTE_COUNT, "invalid image location attribute");
+ // Extract length of data (in bytes).
u1 n = attribute_length(byte);
- assert(kind < ATTRIBUTE_COUNT, "invalid image location attribute");
+ // Read value (most significant first.)
_attributes[kind] = attribute_value(data + 1, n);
+ // Position to next attribute by skipping attribute header and data bytes.
data += n + 1;
}
}
-ImageFile::ImageFile(const char* name) {
+// Zero all attribute values.
+void ImageLocation::clear_data() {
+ // Set defaults to zero.
+ memset(_attributes, 0, sizeof(_attributes));
+}
+
+// ImageModuleData constructor maps out sub-tables for faster access.
+ImageModuleData::ImageModuleData(const ImageFileReader* image_file,
+ const char* module_data_name) :
+ _image_file(image_file),
+ _endian(image_file->endian()),
+ _strings(image_file->get_strings()) {
+ // Retrieve the resource containing the module data for the image file.
+ ImageLocation location;
+ bool found = image_file->find_location(module_data_name, location);
+ guarantee(found, "missing module data");
+ u8 data_size = location.get_attribute(ImageLocation::ATTRIBUTE_UNCOMPRESSED);
+ _data = (u1*)NEW_C_HEAP_ARRAY(char, data_size, mtClass);
+ _image_file->get_resource(location, _data);
+ // Map out the header.
+ _header = (Header*)_data;
+ // Get the package to module entry count.
+ u4 ptm_count = _header->ptm_count(_endian);
+ // Get the module to package entry count.
+ u4 mtp_count = _header->mtp_count(_endian);
+ // Compute the offset of the package to module perfect hash redirect.
+ u4 ptm_redirect_offset = sizeof(Header);
+ // Compute the offset of the package to module data.
+ u4 ptm_data_offset = ptm_redirect_offset + ptm_count * sizeof(s4);
+ // Compute the offset of the module to package perfect hash redirect.
+ u4 mtp_redirect_offset = ptm_data_offset + ptm_count * sizeof(PTMData);
+ // Compute the offset of the module to package data.
+ u4 mtp_data_offset = mtp_redirect_offset + mtp_count * sizeof(s4);
+ // Compute the offset of the module to package tables.
+ u4 mtp_packages_offset = mtp_data_offset + mtp_count * sizeof(MTPData);
+ // Compute the address of the package to module perfect hash redirect.
+ _ptm_redirect = (s4*)(_data + ptm_redirect_offset);
+ // Compute the address of the package to module data.
+ _ptm_data = (PTMData*)(_data + ptm_data_offset);
+ // Compute the address of the module to package perfect hash redirect.
+ _mtp_redirect = (s4*)(_data + mtp_redirect_offset);
+ // Compute the address of the module to package data.
+ _mtp_data = (MTPData*)(_data + mtp_data_offset);
+ // Compute the address of the module to package tables.
+ _mtp_packages = (s4*)(_data + mtp_packages_offset);
+}
+
+// Release module data resource.
+ImageModuleData::~ImageModuleData() {
+ if (_data != NULL) {
+ FREE_C_HEAP_ARRAY(u1, _data);
+ }
+}
+
+// Return the name of the module data resource. Ex. "./lib/modules/file.jimage"
+// yields "file.jdata"
+void ImageModuleData::module_data_name(char* buffer, const char* image_file_name) {
+ // Locate the last slash in the file name path.
+ const char* slash = strrchr(image_file_name, os::file_separator()[0]);
+ // Trim the path to name and extension.
+ const char* name = slash != NULL ? slash + 1 : (char *)image_file_name;
+ // Locate the extension period.
+ const char* dot = strrchr(name, '.');
+ guarantee(dot, "missing extension on jimage name");
+ // Trim to only base name.
+ int length = dot - name;
+ strncpy(buffer, name, length);
+ buffer[length] = '\0';
+ // Append extension.
+ strcat(buffer, ".jdata");
+}
+
+// Return the module in which a package resides. Returns NULL if not found.
+const char* ImageModuleData::package_to_module(const char* package_name) {
+ // Search the package to module table.
+ s4 index = ImageStrings::find(_endian, package_name, _ptm_redirect,
+ _header->ptm_count(_endian));
+ // If entry is found.
+ if (index != ImageStrings::NOT_FOUND) {
+ // Retrieve the package to module entry.
+ PTMData* data = _ptm_data + index;
+ // Verify that it is the correct data.
+ if (strcmp(package_name, get_string(data->name_offset(_endian))) != 0) {
+ return NULL;
+ }
+ // Return the module name.
+ return get_string(data->module_name_offset(_endian));
+ }
+ return NULL;
+}
+
+// Returns all the package names in a module. Returns NULL if module not found.
+GrowableArray<const char*>* ImageModuleData::module_to_packages(const char* module_name) {
+ // Search the module to package table.
+ s4 index = ImageStrings::find(_endian, module_name, _mtp_redirect,
+ _header->mtp_count(_endian));
+ // If entry is found.
+ if (index != ImageStrings::NOT_FOUND) {
+ // Retrieve the module to package entry.
+ MTPData* data = _mtp_data + index;
+ // Verify that it is the correct data.
+ if (strcmp(module_name, get_string(data->name_offset(_endian))) != 0) {
+ return NULL;
+ }
+ // Construct an array of all the package entries.
+ GrowableArray<const char*>* packages = new GrowableArray<const char*>();
+ s4 package_offset = data->package_offset(_endian);
+ for (u4 i = 0; i < data->package_count(_endian); i++) {
+ u4 package_name_offset = mtp_package(package_offset + i);
+ const char* package_name = get_string(package_name_offset);
+ packages->append(package_name);
+ }
+ return packages;
+ }
+ return NULL;
+}
+
+// Table to manage multiple opens of an image file.
+GrowableArray<ImageFileReader*>* ImageFileReader::_reader_table =
+ new(ResourceObj::C_HEAP, mtInternal) GrowableArray<ImageFileReader*>(2, true);
+
+// Open an image file, reuse structure if file already open.
+ImageFileReader* ImageFileReader::open(const char* name, bool big_endian) {
+ // Lock out _reader_table.
+ MutexLocker ml(ImageFileReaderTable_lock);
+ ImageFileReader* reader;
+ // Search for an exist image file.
+ for (int i = 0; i < _reader_table->length(); i++) {
+ // Retrieve table entry.
+ reader = _reader_table->at(i);
+ // If name matches, then reuse (bump up use count.)
+ if (strcmp(reader->name(), name) == 0) {
+ reader->inc_use();
+ return reader;
+ }
+ }
+ // Need a new image reader.
+ reader = new ImageFileReader(name, big_endian);
+ bool opened = reader->open();
+ // If failed to open.
+ if (!opened) {
+ delete reader;
+ return NULL;
+ }
+ // Bump use count and add to table.
+ reader->inc_use();
+ _reader_table->append(reader);
+ return reader;
+}
+
+// Close an image file if the file is not in use elsewhere.
+void ImageFileReader::close(ImageFileReader *reader) {
+ // Lock out _reader_table.
+ MutexLocker ml(ImageFileReaderTable_lock);
+ // If last use then remove from table and then close.
+ if (reader->dec_use()) {
+ _reader_table->remove(reader);
+ delete reader;
+ }
+}
+
+// Return an id for the specifed ImageFileReader.
+u8 ImageFileReader::readerToID(ImageFileReader *reader) {
+ // ID is just the cloaked reader address.
+ return (u8)reader;
+}
+
+// Validate the image id.
+bool ImageFileReader::idCheck(u8 id) {
+ // Make sure the ID is a managed (_reader_table) reader.
+ MutexLocker ml(ImageFileReaderTable_lock);
+ return _reader_table->contains((ImageFileReader*)id);
+}
+
+// Return an id for the specifed ImageFileReader.
+ImageFileReader* ImageFileReader::idToReader(u8 id) {
+#ifdef PRODUCT
+ // Fast convert.
+ return (ImageFileReader*)id;
+#else
+ // Do a slow check before fast convert.
+ return idCheck(id) ? (ImageFileReader*)id : NULL;
+#endif
+}
+
+// Constructor intializes to a closed state.
+ImageFileReader::ImageFileReader(const char* name, bool big_endian) {
// Copy the image file name.
- _name = NEW_C_HEAP_ARRAY(char, strlen(name)+1, mtClass);
+ _name = NEW_C_HEAP_ARRAY(char, strlen(name) + 1, mtClass);
strcpy(_name, name);
-
// Initialize for a closed file.
_fd = -1;
- _memory_mapped = true;
+ _endian = Endian::get_handler(big_endian);
_index_data = NULL;
}
-ImageFile::~ImageFile() {
+// Close image and free up data structures.
+ImageFileReader::~ImageFileReader() {
// Ensure file is closed.
close();
-
// Free up name.
+ if (_name != NULL) {
FREE_C_HEAP_ARRAY(char, _name);
+ _name = NULL;
+ }
}
-bool ImageFile::open() {
+// Open image file for read access.
+bool ImageFileReader::open() {
// If file exists open for reading.
struct stat st;
if (os::stat(_name, &st) != 0 ||
(st.st_mode & S_IFREG) != S_IFREG ||
(_fd = os::open(_name, 0, O_RDONLY)) == -1) {
return false;
}
-
- // Read image file header and verify.
- u8 header_size = sizeof(ImageHeader);
- if (os::read(_fd, &_header, header_size) != header_size ||
- _header._magic != IMAGE_MAGIC ||
- _header._major_version != MAJOR_VERSION ||
- _header._minor_version != MINOR_VERSION) {
+ // Retrieve the file size.
+ _file_size = (u8)st.st_size;
+ // Read image file header and verify it has a valid header.
+ size_t header_size = sizeof(ImageHeader);
+ if (_file_size < header_size ||
+ !read_at((u1*)&_header, header_size, 0) ||
+ _header.magic(_endian) != IMAGE_MAGIC ||
+ _header.major_version(_endian) != MAJOR_VERSION ||
+ _header.minor_version(_endian) != MINOR_VERSION) {
close();
return false;
}
-
- // Memory map index.
+ // Size of image index.
_index_size = index_size();
- _index_data = (u1*)os::map_memory(_fd, _name, 0, NULL, _index_size, true, false);
-
- // Failing that, read index into C memory.
- if (_index_data == NULL) {
- _memory_mapped = false;
- _index_data = NEW_RESOURCE_ARRAY(u1, _index_size);
-
- if (os::seek_to_file_offset(_fd, 0) == -1) {
- close();
+ // Make sure file is large enough to contain the index.
+ if (_file_size < _index_size) {
return false;
}
-
- if (os::read(_fd, _index_data, _index_size) != _index_size) {
- close();
- return false;
- }
-
- return true;
- }
-
-// Used to advance a pointer, unstructured.
-#undef nextPtr
-#define nextPtr(base, fromType, count, toType) (toType*)((fromType*)(base) + (count))
- // Pull tables out from the index.
- _redirect_table = nextPtr(_index_data, u1, header_size, s4);
- _offsets_table = nextPtr(_redirect_table, s4, _header._location_count, u4);
- _location_bytes = nextPtr(_offsets_table, u4, _header._location_count, u1);
- _string_bytes = nextPtr(_location_bytes, u1, _header._locations_size, u1);
-#undef nextPtr
-
+ // Determine how much of the image is memory mapped.
+ off_t map_size = (off_t)(MemoryMapImage ? _file_size : _index_size);
+ // Memory map image (minimally the index.)
+ _index_data = (u1*)os::map_memory(_fd, _name, 0, NULL, map_size, true, false);
+ guarantee(_index_data, "image file not memory mapped");
+ // Retrieve length of index perfect hash table.
+ u4 length = table_length();
+ // Compute offset of the perfect hash table redirect table.
+ u4 redirect_table_offset = (u4)header_size;
+ // Compute offset of index attribute offsets.
+ u4 offsets_table_offset = redirect_table_offset + length * sizeof(s4);
+ // Compute offset of index location attribute data.
+ u4 location_bytes_offset = offsets_table_offset + length * sizeof(u4);
+ // Compute offset of index string table.
+ u4 string_bytes_offset = location_bytes_offset + locations_size();
+ // Compute address of the perfect hash table redirect table.
+ _redirect_table = (s4*)(_index_data + redirect_table_offset);
+ // Compute address of index attribute offsets.
+ _offsets_table = (u4*)(_index_data + offsets_table_offset);
+ // Compute address of index location attribute data.
+ _location_bytes = _index_data + location_bytes_offset;
+ // Compute address of index string table.
+ _string_bytes = _index_data + string_bytes_offset;
// Successful open.
return true;
}
-void ImageFile::close() {
+// Close image file.
+void ImageFileReader::close() {
// Dealllocate the index.
- if (_index_data) {
- if (_memory_mapped) {
+ if (_index_data != NULL) {
os::unmap_memory((char*)_index_data, _index_size);
- } else {
- FREE_RESOURCE_ARRAY(u1, _index_data, _index_size);
- }
-
_index_data = NULL;
}
-
- // close file.
+ // Close file.
if (_fd != -1) {
os::close(_fd);
_fd = -1;
}
-
}
-// Return the attribute stream for a named resourced.
-u1* ImageFile::find_location_data(const char* path) const {
- // Compute hash.
- u4 hash = ImageStrings::hash_code(path) % _header._location_count;
- s4 redirect = _redirect_table[hash];
-
- if (!redirect) {
- return NULL;
+// Read directly from the file.
+bool ImageFileReader::read_at(u1* data, u8 size, u8 offset) const {
+ return os::read_at(_fd, data, size, offset) == size;
+}
+
+// Find the location attributes associated with the path. Returns true if
+// the location is found, false otherwise.
+bool ImageFileReader::find_location(const char* path, ImageLocation& location) const {
+ // Locate the entry in the index perfect hash table.
+ s4 index = ImageStrings::find(_endian, path, _redirect_table, table_length());
+ // If is found.
+ if (index != ImageStrings::NOT_FOUND) {
+ // Get address of first byte of location attribute stream.
+ u1* data = get_location_data(index);
+ // Expand location attributes.
+ location.set_data(data);
+ // Make sure result is not a false positive.
+ return verify_location(location, path);
}
+ return false;
+}
- u4 index;
-
- if (redirect < 0) {
- // If no collision.
- index = -redirect - 1;
- } else {
- // If collision, recompute hash code.
- index = ImageStrings::hash_code(path, redirect) % _header._location_count;
+// Assemble the location path from the string fragments indicated in the location attributes.
+void ImageFileReader::location_path(ImageLocation& location, char* path, size_t max) const {
+ // Manage the image string table.
+ ImageStrings strings(_string_bytes, _header.strings_size(_endian));
+ // Position to first character of the path buffer.
+ char* next = path;
+ // Temp for string length.
+ size_t length;
+ // Get module string.
+ const char* module = location.get_attribute(ImageLocation::ATTRIBUTE_MODULE, strings);
+ // If module string is not empty string.
+ if (*module != '\0') {
+ // Get length of module name.
+ length = strlen(module);
+ // Make sure there is no buffer overflow.
+ guarantee(next - path + length + 2 < max, "buffer overflow");
+ // Append '/module/'.
+ *next++ = '/';
+ strcpy(next, module); next += length;
+ *next++ = '/';
}
-
- assert(index < _header._location_count, "index exceeds location count");
- u4 offset = _offsets_table[index];
- assert(offset < _header._locations_size, "offset exceeds location attributes size");
-
- if (offset == 0) {
- return NULL;
+ // Get parent (package) string.
+ const char* parent = location.get_attribute(ImageLocation::ATTRIBUTE_PARENT, strings);
+ // If parent string is not empty string.
+ if (*parent != '\0') {
+ // Get length of module string.
+ length = strlen(parent);
+ // Make sure there is no buffer overflow.
+ guarantee(next - path + length + 1 < max, "buffer overflow");
+ // Append 'patent/' .
+ strcpy(next, parent); next += length;
+ *next++ = '/';
}
-
- return _location_bytes + offset;
-}
-
-// Verify that a found location matches the supplied path.
-bool ImageFile::verify_location(ImageLocation& location, const char* path) const {
- // Retrieve each path component string.
- ImageStrings strings(_string_bytes, _header._strings_size);
- // Match a path with each subcomponent without concatenation (copy).
- // Match up path parent.
+ // Get base name string.
+ const char* base = location.get_attribute(ImageLocation::ATTRIBUTE_BASE, strings);
+ // Get length of base name.
+ length = strlen(base);
+ // Make sure there is no buffer overflow.
+ guarantee(next - path + length < max, "buffer overflow");
+ // Append base name.
+ strcpy(next, base); next += length;
+ // Get extension string.
+ const char* extension = location.get_attribute(ImageLocation::ATTRIBUTE_EXTENSION, strings);
+ // If extension string is not empty string.
+ if (*extension != '\0') {
+ // Get length of extension string.
+ length = strlen(extension);
+ // Make sure there is no buffer overflow.
+ guarantee(next - path + length + 1 < max, "buffer overflow");
+ // Append '.extension' .
+ *next++ = '.';
+ strcpy(next, extension); next += length;
+ }
+ // Make sure there is no buffer overflow.
+ guarantee((size_t)(next - path) < max, "buffer overflow");
+ // Terminate string.
+ *next = '\0';
+}
+
+// Verify that a found location matches the supplied path (without copying.)
+bool ImageFileReader::verify_location(ImageLocation& location, const char* path) const {
+ // Manage the image string table.
+ ImageStrings strings(_string_bytes, _header.strings_size(_endian));
+ // Position to first character of the path string.
+ const char* next = path;
+ // Get module name string.
+ const char* module = location.get_attribute(ImageLocation::ATTRIBUTE_MODULE, strings);
+ // If module string is not empty.
+ if (*module != '\0') {
+ // Compare '/module/' .
+ if (*next++ != '/') return false;
+ if (!(next = ImageStrings::starts_with(next, module))) return false;
+ if (*next++ != '/') return false;
+ }
+ // Get parent (package) string
const char* parent = location.get_attribute(ImageLocation::ATTRIBUTE_PARENT, strings);
- const char* next = ImageStrings::starts_with(path, parent);
- // Continue only if a complete match.
- if (!next) return false;
- // Match up path base.
+ // If parent string is not empty string.
+ if (*parent != '\0') {
+ // Compare 'parent/' .
+ if (!(next = ImageStrings::starts_with(next, parent))) return false;
+ if (*next++ != '/') return false;
+ }
+ // Get base name string.
const char* base = location.get_attribute(ImageLocation::ATTRIBUTE_BASE, strings);
- next = ImageStrings::starts_with(next, base);
- // Continue only if a complete match.
- if (!next) return false;
- // Match up path extension.
+ // Compare with basne name.
+ if (!(next = ImageStrings::starts_with(next, base))) return false;
+ // Get extension string.
const char* extension = location.get_attribute(ImageLocation::ATTRIBUTE_EXTENSION, strings);
- next = ImageStrings::starts_with(next, extension);
-
+ // If extension is not empty.
+ if (*extension != '\0') {
+ // Compare '.extension' .
+ if (*next++ != '.') return false;
+ if (!(next = ImageStrings::starts_with(next, extension))) return false;
+ }
// True only if complete match and no more characters.
- return next && *next == '\0';
+ return *next == '\0';
}
-// Return the resource for the supplied location.
-u1* ImageFile::get_resource(ImageLocation& location) const {
+// Return the resource data for the supplied location.
+void ImageFileReader::get_resource(ImageLocation& location, u1* uncompressed_data) const {
// Retrieve the byte offset and size of the resource.
- u8 offset = _index_size + location.get_attribute(ImageLocation::ATTRIBUTE_OFFSET);
- u8 size = location.get_attribute(ImageLocation::ATTRIBUTE_UNCOMPRESSED);
+ u8 offset = location.get_attribute(ImageLocation::ATTRIBUTE_OFFSET);
+ u8 uncompressed_size = location.get_attribute(ImageLocation::ATTRIBUTE_UNCOMPRESSED);
u8 compressed_size = location.get_attribute(ImageLocation::ATTRIBUTE_COMPRESSED);
- u8 read_size = compressed_size ? compressed_size : size;
-
- // Allocate space for the resource.
- u1* data = NEW_RESOURCE_ARRAY(u1, read_size);
-
- bool is_read = os::read_at(_fd, data, read_size, offset) == read_size;
+ if (compressed_size != 0) {
+ ResourceMark rm;
+ u1* compressed_data;
+ // If not memory mapped read in bytes.
+ if (!MemoryMapImage) {
+ // Allocate buffer for compression.
+ compressed_data = NEW_RESOURCE_ARRAY(u1, compressed_size);
+ // Read bytes from offset beyond the image index.
+ bool is_read = read_at(compressed_data, compressed_size, _index_size + offset);
guarantee(is_read, "error reading from image or short read");
-
- // If not compressed, just return the data.
- if (!compressed_size) {
- return data;
- }
-
- u1* uncompressed = NEW_RESOURCE_ARRAY(u1, size);
- char* msg = NULL;
- jboolean res = ClassLoader::decompress(data, compressed_size, uncompressed, size, &msg);
- if (!res) warning("decompression failed due to %s\n", msg);
- guarantee(res, "decompression failed");
-
- return uncompressed;
-}
-
-void ImageFile::get_resource(const char* path, u1*& buffer, u8& size) const {
- buffer = NULL;
- size = 0;
- u1* data = find_location_data(path);
- if (data) {
- ImageLocation location(data);
- if (verify_location(location, path)) {
- size = location.get_attribute(ImageLocation::ATTRIBUTE_UNCOMPRESSED);
- buffer = get_resource(location);
- }
+ } else {
+ compressed_data = get_data_address() + offset;
}
-}
-
-GrowableArray<const char*>* ImageFile::packages(const char* name) {
- char entry[JVM_MAXPATHLEN];
- bool overflow = jio_snprintf(entry, sizeof(entry), "%s/packages.offsets", name) == -1;
- guarantee(!overflow, "package name overflow");
-
- u1* buffer;
- u8 size;
-
- get_resource(entry, buffer, size);
- guarantee(buffer, "missing module packages reource");
- ImageStrings strings(_string_bytes, _header._strings_size);
- GrowableArray<const char*>* pkgs = new GrowableArray<const char*>();
- int count = size / 4;
- for (int i = 0; i < count; i++) {
- u4 offset = Bytes::get_Java_u4(buffer + (i*4));
- const char* p = strings.get(offset);
- pkgs->append(p);
+ // Get image string table.
+ const ImageStrings strings = get_strings();
+ // Decompress resource.
+ ImageDecompressor::decompress_resource(compressed_data, uncompressed_data, uncompressed_size,
+ &strings, false);
+ } else {
+ // Read bytes from offset beyond the image index.
+ bool is_read = read_at(uncompressed_data, uncompressed_size, _index_size + offset);
+ guarantee(is_read, "error reading from image or short read");
}
-
- return pkgs;
}
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