Add a ZipArchiveStreamEntry class.
This allows someone to stream the data out of a zip archive
instead of extracting to a file or to memory.
Included in this change is a small cleanup of the makefile.
Change-Id: I8b679a679c3502ff4ea0bc4f9e918303657fa424
diff --git a/libziparchive/zip_archive_stream_entry.cc b/libziparchive/zip_archive_stream_entry.cc
new file mode 100644
index 0000000..f618835
--- /dev/null
+++ b/libziparchive/zip_archive_stream_entry.cc
@@ -0,0 +1,305 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Read-only stream access to Zip Archive entries.
+#include <errno.h>
+#include <inttypes.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <memory>
+#include <vector>
+
+#define LOG_TAG "ZIPARCHIVE"
+#include <android-base/file.h>
+#include <log/log.h>
+#include <ziparchive/zip_archive.h>
+#include <ziparchive/zip_archive_stream_entry.h>
+#include <zlib.h>
+
+#include "zip_archive_private.h"
+
+static constexpr size_t kBufSize = 65535;
+
+bool ZipArchiveStreamEntry::Init(const ZipEntry& entry) {
+ ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle_);
+ off64_t data_offset = entry.offset;
+ if (lseek64(archive->fd, data_offset, SEEK_SET) != data_offset) {
+ ALOGW("lseek to data at %" PRId64 " failed: %s", data_offset, strerror(errno));
+ return false;
+ }
+ crc32_ = entry.crc32;
+ return true;
+}
+
+class ZipArchiveStreamEntryUncompressed : public ZipArchiveStreamEntry {
+ public:
+ ZipArchiveStreamEntryUncompressed(ZipArchiveHandle handle) : ZipArchiveStreamEntry(handle) {}
+ virtual ~ZipArchiveStreamEntryUncompressed() {}
+
+ const std::vector<uint8_t>* Read() override;
+
+ bool Verify() override;
+
+ protected:
+ bool Init(const ZipEntry& entry) override;
+
+ uint32_t length_;
+
+ private:
+ std::vector<uint8_t> data_;
+ uint32_t computed_crc32_;
+};
+
+bool ZipArchiveStreamEntryUncompressed::Init(const ZipEntry& entry) {
+ if (!ZipArchiveStreamEntry::Init(entry)) {
+ return false;
+ }
+
+ length_ = entry.uncompressed_length;
+
+ data_.resize(kBufSize);
+ computed_crc32_ = 0;
+
+ return true;
+}
+
+const std::vector<uint8_t>* ZipArchiveStreamEntryUncompressed::Read() {
+ if (length_ == 0) {
+ return nullptr;
+ }
+
+ size_t bytes = (length_ > data_.size()) ? data_.size() : length_;
+ ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle_);
+ errno = 0;
+ if (!android::base::ReadFully(archive->fd, data_.data(), bytes)) {
+ if (errno != 0) {
+ ALOGE("Error reading from archive fd: %s", strerror(errno));
+ } else {
+ ALOGE("Short read of zip file, possibly corrupted zip?");
+ }
+ length_ = 0;
+ return nullptr;
+ }
+
+ if (bytes < data_.size()) {
+ data_.resize(bytes);
+ }
+ computed_crc32_ = crc32(computed_crc32_, data_.data(), data_.size());
+ length_ -= bytes;
+ return &data_;
+}
+
+bool ZipArchiveStreamEntryUncompressed::Verify() {
+ return length_ == 0 && crc32_ == computed_crc32_;
+}
+
+class ZipArchiveStreamEntryCompressed : public ZipArchiveStreamEntry {
+ public:
+ ZipArchiveStreamEntryCompressed(ZipArchiveHandle handle) : ZipArchiveStreamEntry(handle) {}
+ virtual ~ZipArchiveStreamEntryCompressed();
+
+ const std::vector<uint8_t>* Read() override;
+
+ bool Verify() override;
+
+ protected:
+ bool Init(const ZipEntry& entry) override;
+
+ private:
+ bool z_stream_init_ = false;
+ z_stream z_stream_;
+ std::vector<uint8_t> in_;
+ std::vector<uint8_t> out_;
+ uint32_t uncompressed_length_;
+ uint32_t compressed_length_;
+ uint32_t computed_crc32_;
+};
+
+// This method is using libz macros with old-style-casts
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wold-style-cast"
+static inline int zlib_inflateInit2(z_stream* stream, int window_bits) {
+ return inflateInit2(stream, window_bits);
+}
+#pragma GCC diagnostic pop
+
+bool ZipArchiveStreamEntryCompressed::Init(const ZipEntry& entry) {
+ if (!ZipArchiveStreamEntry::Init(entry)) {
+ return false;
+ }
+
+ // Initialize the zlib stream struct.
+ memset(&z_stream_, 0, sizeof(z_stream_));
+ z_stream_.zalloc = Z_NULL;
+ z_stream_.zfree = Z_NULL;
+ z_stream_.opaque = Z_NULL;
+ z_stream_.next_in = nullptr;
+ z_stream_.avail_in = 0;
+ z_stream_.avail_out = 0;
+ z_stream_.data_type = Z_UNKNOWN;
+
+ // Use the undocumented "negative window bits" feature to tell zlib
+ // that there's no zlib header waiting for it.
+ int zerr = zlib_inflateInit2(&z_stream_, -MAX_WBITS);
+ if (zerr != Z_OK) {
+ if (zerr == Z_VERSION_ERROR) {
+ ALOGE("Installed zlib is not compatible with linked version (%s)",
+ ZLIB_VERSION);
+ } else {
+ ALOGE("Call to inflateInit2 failed (zerr=%d)", zerr);
+ }
+
+ return false;
+ }
+
+ z_stream_init_ = true;
+
+ uncompressed_length_ = entry.uncompressed_length;
+ compressed_length_ = entry.compressed_length;
+
+ out_.resize(kBufSize);
+ in_.resize(kBufSize);
+
+ computed_crc32_ = 0;
+
+ return true;
+}
+
+ZipArchiveStreamEntryCompressed::~ZipArchiveStreamEntryCompressed() {
+ if (z_stream_init_) {
+ inflateEnd(&z_stream_);
+ z_stream_init_ = false;
+ }
+}
+
+bool ZipArchiveStreamEntryCompressed::Verify() {
+ return z_stream_init_ && uncompressed_length_ == 0 && compressed_length_ == 0 &&
+ crc32_ == computed_crc32_;
+}
+
+const std::vector<uint8_t>* ZipArchiveStreamEntryCompressed::Read() {
+ if (z_stream_.avail_out == 0) {
+ z_stream_.next_out = out_.data();
+ z_stream_.avail_out = out_.size();;
+ }
+
+ while (true) {
+ if (z_stream_.avail_in == 0) {
+ if (compressed_length_ == 0) {
+ return nullptr;
+ }
+ size_t bytes = (compressed_length_ > in_.size()) ? in_.size() : compressed_length_;
+ ZipArchive* archive = reinterpret_cast<ZipArchive*>(handle_);
+ errno = 0;
+ if (!android::base::ReadFully(archive->fd, in_.data(), bytes)) {
+ if (errno != 0) {
+ ALOGE("Error reading from archive fd: %s", strerror(errno));
+ } else {
+ ALOGE("Short read of zip file, possibly corrupted zip?");
+ }
+ return nullptr;
+ }
+
+ compressed_length_ -= bytes;
+ z_stream_.next_in = in_.data();
+ z_stream_.avail_in = bytes;
+ }
+
+ int zerr = inflate(&z_stream_, Z_NO_FLUSH);
+ if (zerr != Z_OK && zerr != Z_STREAM_END) {
+ ALOGE("inflate zerr=%d (nIn=%p aIn=%u nOut=%p aOut=%u)",
+ zerr, z_stream_.next_in, z_stream_.avail_in,
+ z_stream_.next_out, z_stream_.avail_out);
+ return nullptr;
+ }
+
+ if (z_stream_.avail_out == 0) {
+ uncompressed_length_ -= out_.size();
+ computed_crc32_ = crc32(computed_crc32_, out_.data(), out_.size());
+ return &out_;
+ }
+ if (zerr == Z_STREAM_END) {
+ if (z_stream_.avail_out != 0) {
+ // Resize the vector down to the actual size of the data.
+ out_.resize(out_.size() - z_stream_.avail_out);
+ computed_crc32_ = crc32(computed_crc32_, out_.data(), out_.size());
+ uncompressed_length_ -= out_.size();
+ return &out_;
+ }
+ return nullptr;
+ }
+ }
+ return nullptr;
+}
+
+class ZipArchiveStreamEntryRawCompressed : public ZipArchiveStreamEntryUncompressed {
+ public:
+ ZipArchiveStreamEntryRawCompressed(ZipArchiveHandle handle)
+ : ZipArchiveStreamEntryUncompressed(handle) {}
+ virtual ~ZipArchiveStreamEntryRawCompressed() {}
+
+ bool Verify() override;
+
+ protected:
+ bool Init(const ZipEntry& entry) override;
+};
+
+bool ZipArchiveStreamEntryRawCompressed::Init(const ZipEntry& entry) {
+ if (!ZipArchiveStreamEntryUncompressed::Init(entry)) {
+ return false;
+ }
+ length_ = entry.compressed_length;
+
+ return true;
+}
+
+bool ZipArchiveStreamEntryRawCompressed::Verify() {
+ return length_ == 0;
+}
+
+ZipArchiveStreamEntry* ZipArchiveStreamEntry::Create(
+ ZipArchiveHandle handle, const ZipEntry& entry) {
+ ZipArchiveStreamEntry* stream = nullptr;
+ if (entry.method != kCompressStored) {
+ stream = new ZipArchiveStreamEntryCompressed(handle);
+ } else {
+ stream = new ZipArchiveStreamEntryUncompressed(handle);
+ }
+ if (stream && !stream->Init(entry)) {
+ delete stream;
+ stream = nullptr;
+ }
+
+ return stream;
+}
+
+ZipArchiveStreamEntry* ZipArchiveStreamEntry::CreateRaw(
+ ZipArchiveHandle handle, const ZipEntry& entry) {
+ ZipArchiveStreamEntry* stream = nullptr;
+ if (entry.method == kCompressStored) {
+ // Not compressed, don't need to do anything special.
+ stream = new ZipArchiveStreamEntryUncompressed(handle);
+ } else {
+ stream = new ZipArchiveStreamEntryRawCompressed(handle);
+ }
+ if (stream && !stream->Init(entry)) {
+ delete stream;
+ stream = nullptr;
+ }
+ return stream;
+}