emkornfield commented on code in PR #42174: URL: https://github.com/apache/arrow/pull/42174#discussion_r1680385264
########## cpp/tools/parquet/parquet_dump_footer.cc: ########## @@ -0,0 +1,246 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you 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. + +#include <cstdint> +#include <cstring> +#include <exception> +#include <fstream> +#include <iostream> +#include <limits> +#include <optional> +#include <random> + +#include <thrift/protocol/TCompactProtocol.h> +#include <thrift/transport/TBufferTransports.h> + +#include "arrow/filesystem/filesystem.h" +#include "arrow/util/endian.h" +#include "parquet/thrift_internal.h" +#include "generated/parquet_types.h" + +using apache::thrift::protocol::TCompactProtocol; +using apache::thrift::transport::TMemoryBuffer; +using apache::thrift::transport::TTransport; + +namespace { +int PrintHelp() { + std::cerr << R"( +Usage: parquet-dump-footer + -h|--help Print help and exit + --no-scrub Do not scrub potentially PII metadata + --json Output JSON instead of binary + --in Input file: required + --out Output file: defaults to stdout + + Dumps the footer of a Parquet file to stdout or a file, optionally with + potentially PII metadata scrubbed. +)"; + return 1; +} + +uint32_t ReadLE32(const void* p) { + uint32_t x; + memcpy(&x, p, sizeof(x)); + return arrow::bit_util::FromLittleEndian(x); +} + +void AppendLE32(uint32_t v, std::string* out) { + v = arrow::bit_util::ToLittleEndian(v); + out->append(reinterpret_cast<const char*>(&v), sizeof(v)); +} + +template <typename T> +bool Deserialize(const char* data, uint32_t len, T* obj) { + parquet::ThriftDeserializer des(/*string_size_limit=*/10 << 20, + /*container_size_limit=*/10 << 20); + try { + des.DeserializeMessage(reinterpret_cast<const uint8_t*>(data), &len, obj); + return true; + } catch (const std::exception& e) { + std::cerr << "Failed to deserialize: " << e.what() << "\n"; + return false; + } +} + +template <typename T> +bool Serialize(const T& obj, std::string* out) { + parquet::ThriftSerializer ser(/*initial_buffer_size=*/10 << 20); + try { + ser.SerializeToString(&obj, out); + return true; + } catch (const std::exception& e) { + std::cerr << "Failed to serialize: " << e.what() << "\n"; + return false; + } +} + +// Replace the contents of s with random data of the same length. +void Scrub(std::string* s) { + static char pool[4096]; + static std::mt19937 rng(std::random_device {}()); + static const bool kPoolInit = [] { + std::uniform_int_distribution<> caps(65, 90); + for (size_t i = 0; i < sizeof(pool); i++) pool[i] = caps(rng); + return true; + }(); + (void)kPoolInit; + + const size_t n = s->size(); + s->clear(); + while (s->size() < n) { + size_t m = std::min(n, sizeof(pool) / 2); + std::uniform_int_distribution<> start(0, sizeof(pool) / 2); + s->append(&pool[start(rng)], m); + } +} + +void Scrub(parquet::format::FileMetaData* md) { + for (auto& s : md->schema) { + Scrub(&s.name); + } + for (auto& r : md->row_groups) { + for (auto& c : r.columns) { + Scrub(&c.file_path); + if (c.__isset.meta_data) { + auto& m = c.meta_data; + for (auto& p : m.path_in_schema) Scrub(&p); + for (auto& kv : m.key_value_metadata) { + Scrub(&kv.key); + Scrub(&kv.value); + } + Scrub(&m.statistics.max_value); + Scrub(&m.statistics.min_value); + Scrub(&m.statistics.min); + Scrub(&m.statistics.max); + } + + if (c.crypto_metadata.__isset.ENCRYPTION_WITH_COLUMN_KEY) { + auto& m = c.crypto_metadata.ENCRYPTION_WITH_COLUMN_KEY; + for (auto& p : m.path_in_schema) Scrub(&p); + Scrub(&m.key_metadata); + } + Scrub(&c.encrypted_column_metadata); + } + } + for (auto& kv : md->key_value_metadata) { + Scrub(&kv.key); + Scrub(&kv.value); + } + Scrub(&md->footer_signing_key_metadata); +} + +// Returns: +// - 0 on success +// - -1 on error +// - the size of the footer if tail is too small +int64_t ParseFooter(const std::string& tail, parquet::format::FileMetaData* md) { + if (tail.size() > std::numeric_limits<int32_t>::max()) return -1; + + const char* p = tail.data(); + const int32_t n = static_cast<int32_t>(tail.size()); + int32_t len = ReadLE32(p + n - 8); + if (len > n - 8) return len; + + if (!Deserialize(tail.data() + n - 8 - len, len, md)) return -1; + return 0; +} +} // namespace + +int main(int argc, char** argv) { + bool help = false; + bool scrub = true; + bool json = false; + std::string in; + std::string out; + for (int i = 1; i < argc; i++) { + char* arg = argv[i]; + help |= !std::strcmp(arg, "-h") || !std::strcmp(arg, "--help"); Review Comment: OK, I guess manual parsing might be easier. Unless someone better acquanted with CMake can help out. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
