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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
* Ceph distributed storage system
*
* Copyright (C) 2014 Red Hat <contact@redhat.com>
*
* Author: Loic Dachary <loic@dachary.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
*/
#include <errno.h>
#include <stdlib.h>
#include "erasure-code/ErasureCode.h"
#include "global/global_context.h"
#include "common/config.h"
#include "gtest/gtest.h"
using namespace std;
class ErasureCodeTest : public ErasureCode {
public:
map<int, bufferlist> encode_chunks_encoded;
unsigned int k;
unsigned int m;
unsigned int chunk_size;
ErasureCodeTest(unsigned int _k, unsigned int _m, unsigned int _chunk_size) :
k(_k), m(_m), chunk_size(_chunk_size) {}
~ErasureCodeTest() override {}
int init(ErasureCodeProfile &profile, ostream *ss) override {
return 0;
}
unsigned int get_chunk_count() const override { return k + m; }
unsigned int get_data_chunk_count() const override { return k; }
unsigned int get_chunk_size(unsigned int object_size) const override {
return chunk_size;
}
int encode_chunks(const set<int> &want_to_encode,
map<int, bufferlist> *encoded) override {
encode_chunks_encoded = *encoded;
return 0;
}
int decode_chunks(const set<int> &want_to_read,
const map<int, bufferlist> &chunks,
map<int, bufferlist> *decoded) override {
ceph_abort_msg("ErasureCode::decode_chunks not implemented");
}
int create_rule(const string &name,
CrushWrapper &crush,
ostream *ss) const override { return 0; }
};
/*
* If we have a buffer of 5 bytes (X below) and a chunk size of 3
* bytes, for k=3, m=1 an additional 7 bytes (P and C below) will
* need to be allocated for padding (P) and the 3 coding bytes (C).
*
* X -+ +----------+ +-X
* X | | data 0 | | X
* X | +----------+ | X
* X | +----------+ | X -> +-X
* X -+ | data 1 | +-X -> | X
* P -+ +----------+ | P
* P | +----------+ | P
* P | | data 2 | | P
* P | +----------+ | P
* C | +----------+ | C
* C | | coding 3 | | C
* C -+ +----------+ +-C
*
* The data chunks 1 and 2 (data 1 and data 2 above) overflow the
* original buffer because it needs padding. A new buffer will
* be allocated to contain the chunk that overflows and all other
* chunks after it, including the coding chunk(s).
*
* The following test creates a siguation where the buffer provided
* for encoding is not memory aligned. After encoding it asserts that:
*
* a) each chunk is SIMD aligned
* b) the data 1 chunk content is as expected which implies that its
* content has been copied over.
*
* It is possible for a flawed implementation to pas the test because the
* underlying allocation function enforces it.
*/
TEST(ErasureCodeTest, encode_memory_align)
{
int k = 3;
int m = 1;
unsigned chunk_size = ErasureCode::SIMD_ALIGN * 7;
ErasureCodeTest erasure_code(k, m, chunk_size);
set<int> want_to_encode;
for (unsigned int i = 0; i < erasure_code.get_chunk_count(); i++)
want_to_encode.insert(i);
string data(chunk_size + chunk_size / 2, 'X'); // uses 1.5 chunks out of 3
// make sure nothing is memory aligned
bufferptr ptr(buffer::create_aligned(data.length() + 1, ErasureCode::SIMD_ALIGN));
ptr.copy_in(1, data.length(), data.c_str());
ptr.set_offset(1);
ptr.set_length(data.length());
bufferlist in;
in.append(ptr);
map<int, bufferlist> encoded;
ASSERT_FALSE(in.is_aligned(ErasureCode::SIMD_ALIGN));
ASSERT_EQ(0, erasure_code.encode(want_to_encode, in, &encoded));
for (unsigned int i = 0; i < erasure_code.get_chunk_count(); i++)
ASSERT_TRUE(encoded[i].is_aligned(ErasureCode::SIMD_ALIGN));
for (unsigned i = 0; i < chunk_size / 2; i++)
ASSERT_EQ(encoded[1][i], 'X');
ASSERT_NE(encoded[1][chunk_size / 2], 'X');
}
TEST(ErasureCodeTest, encode_misaligned_non_contiguous)
{
int k = 3;
int m = 1;
unsigned chunk_size = ErasureCode::SIMD_ALIGN * 7;
ErasureCodeTest erasure_code(k, m, chunk_size);
set<int> want_to_encode;
for (unsigned int i = 0; i < erasure_code.get_chunk_count(); i++)
want_to_encode.insert(i);
string data(chunk_size, 'X');
// create a non contiguous bufferlist where the frist and the second
// bufferptr are not size aligned although they are memory aligned
bufferlist in;
{
bufferptr ptr(buffer::create_aligned(data.length() - 1, ErasureCode::SIMD_ALIGN));
in.append(ptr);
}
{
bufferptr ptr(buffer::create_aligned(data.length() + 1, ErasureCode::SIMD_ALIGN));
in.append(ptr);
}
map<int, bufferlist> encoded;
ASSERT_FALSE(in.is_contiguous());
ASSERT_TRUE(in.front().is_aligned(ErasureCode::SIMD_ALIGN));
ASSERT_FALSE(in.front().is_n_align_sized(chunk_size));
ASSERT_TRUE(in.back().is_aligned(ErasureCode::SIMD_ALIGN));
ASSERT_FALSE(in.back().is_n_align_sized(chunk_size));
ASSERT_EQ(0, erasure_code.encode(want_to_encode, in, &encoded));
for (unsigned int i = 0; i < erasure_code.get_chunk_count(); i++) {
ASSERT_TRUE(encoded[i].is_aligned(ErasureCode::SIMD_ALIGN));
ASSERT_TRUE(encoded[i].is_n_align_sized(chunk_size));
}
}
/*
* Local Variables:
* compile-command: "cd ../.. ;
* make -j4 unittest_erasure_code &&
* valgrind --tool=memcheck --leak-check=full \
* ./unittest_erasure_code \
* --gtest_filter=*.* --log-to-stderr=true"
* End:
*/
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