test/test_map.cpp

/*
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 *
 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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#include "cx/hash_map.h"
#include "cx/utils.h"
#include "util_allocator.h"

#include <gtest/gtest.h>
#include <unordered_map>
#include <unordered_set>

struct map_operation {
    enum {
        put, rm
    } op;
    char const *key;
    char const *value;
};

auto generate_map_operations() -> std::vector<map_operation> {
    return {
            {map_operation::put, "key 1",          "test"},
            {map_operation::put, "key 2",          "blub"},
            {map_operation::put, "key 3",          "hallo"},
            {map_operation::put, "key 2",          "foobar"},
            {map_operation::put, "key 4",          "value 4"},
            {map_operation::put, "key 5",          "value 5"},
            {map_operation::put, "key 6",          "value 6"},
            {map_operation::rm,  "key 4",          nullptr},
            {map_operation::put, "key 7",          "value 7"},
            {map_operation::put, "key 8",          "value 8"},
            {map_operation::rm,  "does not exist", nullptr},
            {map_operation::put, "key 9",          "value 9"},
            {map_operation::put, "key 6",          "other value"},
            {map_operation::put, "key 7",          "something else"},
            {map_operation::rm,  "key 8",          nullptr},
            {map_operation::rm,  "key 2",          nullptr},
            {map_operation::put, "key 8",          "new value"},
    };
}

static void verify_map_contents(
        CxMap *map,
        std::unordered_map<std::string, std::string> const &refmap
) {
    // verify key iterator
    {
        auto keyiter = cxMapIteratorKeys(map);
        std::unordered_set<std::string> keys;
        cx_foreach(CxHashKey*, elem, keyiter) {
            // we use that our test keys contain NULL-terminated strings
            keys.insert(std::string(elem->data.cstr));
        }
        EXPECT_EQ(keyiter.index, map->size);
        ASSERT_EQ(keys.size(), map->size);
        for (auto &&k: keys) {
            EXPECT_NE(refmap.find(k), refmap.end());
        }
    }

    // verify value iterator
    {
        auto valiter = cxMapIteratorValues(map);
        std::unordered_set<std::string> values; // we use that the values in our test data are unique strings
        cx_foreach(char const*, elem, valiter) {
            values.insert(std::string(elem));
        }
        EXPECT_EQ(valiter.index, map->size);
        ASSERT_EQ(values.size(), map->size);
        for (auto &&v: values) {
            EXPECT_NE(std::find_if(refmap.begin(), refmap.end(),
                                   [v](auto const &e) { return e.second == v; }), refmap.end());
        }
    }

    // verify pair iterator
    {
        auto pairiter = cxMapIterator(map);
        std::unordered_map<std::string, std::string> pairs;
        cx_foreach(CxMapEntry*, entry, pairiter) {
            pairs[std::string(entry->key->data.cstr)] = std::string((char *) entry->value);
        }
        EXPECT_EQ(pairiter.index, map->size);
        ASSERT_EQ(pairs.size(), refmap.size());
        for (auto &&p: pairs) {
            ASSERT_EQ(p.second, refmap.at(p.first));
        }
    }
}

TEST(CxHashMap, Create) {
    CxTestingAllocator allocator;
    auto map = cxHashMapCreate(&allocator, 0);
    auto hmap = reinterpret_cast<struct cx_hash_map_s *>(map);
    EXPECT_GT(hmap->bucket_count, 0);
    cx_for_n(i, hmap->bucket_count) {
        EXPECT_EQ(hmap->buckets[i], nullptr);
    }
    EXPECT_EQ(map->size, 0);
    EXPECT_EQ(map->allocator, &allocator);

    cxMapDestroy(map);
    EXPECT_TRUE(allocator.verify());
}

TEST(CxHashMap, BasicOperations) {
    // create the map
    CxTestingAllocator allocator;
    auto map = cxHashMapCreate(&allocator, 8);

    // create a reference map
    std::unordered_map<std::string, std::string> refmap;

    // generate operations
    auto ops = generate_map_operations();

    // verify iterators for empty map
    verify_map_contents(map, refmap);

    // execute operations and verify results
    for (auto &&op: ops) {
        CxHashKey key = cx_hash_key_str(op.key);
        key.hash = 0; // force the hash map to compute the hash
        if (op.op == map_operation::put) {
            // execute a put operation and verify that the exact value can be read back
            refmap[std::string(op.key)] = std::string(op.value);
            int result = cxMapPut(map, key, (void *) op.value);
            EXPECT_EQ(result, 0);
            auto added = cxMapGet(map, key);
            EXPECT_EQ(memcmp(op.value, added, strlen(op.value)), 0);
        } else {
            // execute a remove and verify that the removed element was returned (or nullptr)
            auto found = refmap.find(op.key);
            auto removed = cxMapRemove(map, key);
            if (found == refmap.end()) {
                EXPECT_EQ(removed, nullptr);
            } else {
                EXPECT_EQ(std::string((char *) removed), found->second);
                refmap.erase(found);
            }
        }
        // compare the current map state with the reference map
        verify_map_contents(map, refmap);
    }

    // destroy the map and verify the memory (de)allocations
    cxMapDestroy(map);
    EXPECT_TRUE(allocator.verify());
}

TEST(CxHashMap, RemoveViaIterator) {
    CxTestingAllocator allocator;
    auto map = cxHashMapCreate(&allocator, 4);

    cxMapPut(map, cx_hash_key_str("key 1"), (void *) "val 1");
    cxMapPut(map, cx_hash_key_str("key 2"), (void *) "val 2");
    cxMapPut(map, cx_hash_key_str("key 3"), (void *) "val 3");
    cxMapPut(map, cx_hash_key_str("key 4"), (void *) "val 4");
    cxMapPut(map, cx_hash_key_str("key 5"), (void *) "val 5");
    cxMapPut(map, cx_hash_key_str("key 6"), (void *) "val 6");

    auto iter = cxMapIterator(map);
    cx_foreach(CxMapEntry*, entry, iter) {
        if (entry->key->data.cstr[4] % 2 == 1) iter.remove = true;
    }
    EXPECT_EQ(map->size, 3);
    EXPECT_EQ(iter.index, map->size);

    EXPECT_EQ(cxMapGet(map, cx_hash_key_str("key 1")), nullptr);
    EXPECT_NE(cxMapGet(map, cx_hash_key_str("key 2")), nullptr);
    EXPECT_EQ(cxMapGet(map, cx_hash_key_str("key 3")), nullptr);
    EXPECT_NE(cxMapGet(map, cx_hash_key_str("key 4")), nullptr);
    EXPECT_EQ(cxMapGet(map, cx_hash_key_str("key 5")), nullptr);
    EXPECT_NE(cxMapGet(map, cx_hash_key_str("key 6")), nullptr);

    cxMapDestroy(map);
    EXPECT_TRUE(allocator.verify());
}

TEST(CxHashMap, RehashNotRequired) {
    CxTestingAllocator allocator;
    auto map = cxHashMapCreate(&allocator, 8);

    cxMapPut(map, cx_hash_key_str("key 1"), (void *) "val 1");
    cxMapPut(map, cx_hash_key_str("key 2"), (void *) "val 2");
    cxMapPut(map, cx_hash_key_str("key 3"), (void *) "val 3");
    cxMapPut(map, cx_hash_key_str("key 4"), (void *) "val 4");
    cxMapPut(map, cx_hash_key_str("key 5"), (void *) "val 5");
    cxMapPut(map, cx_hash_key_str("key 6"), (void *) "val 6");

    // 6/8 does not exceed 0.75, therefore the function should not rehash
    int result = cxMapRehash(map);
    EXPECT_EQ(result, 0);
    EXPECT_EQ(reinterpret_cast<struct cx_hash_map_s *>(map)->bucket_count, 8);

    cxMapDestroy(map);
    EXPECT_TRUE(allocator.verify());
}

TEST(CxHashMap, Rehash) {
    CxTestingAllocator allocator;
    auto map = cxHashMapCreate(&allocator, 8);

    cxMapPut(map, cx_hash_key_str("key 1"), (void *) "val 1");
    cxMapPut(map, cx_hash_key_str("key 2"), (void *) "val 2");
    cxMapPut(map, cx_hash_key_str("key 3"), (void *) "val 3");
    cxMapPut(map, cx_hash_key_str("key 4"), (void *) "val 4");
    cxMapPut(map, cx_hash_key_str("key 5"), (void *) "val 5");
    cxMapPut(map, cx_hash_key_str("key 6"), (void *) "val 6");
    cxMapPut(map, cx_hash_key_str("key 7"), (void *) "val 7");

    int result = cxMapRehash(map);
    EXPECT_EQ(result, 0);
    EXPECT_EQ(reinterpret_cast<struct cx_hash_map_s *>(map)->bucket_count, 17);
    EXPECT_EQ(map->size, 7);

    EXPECT_EQ(strcmp((char *) cxMapGet(map, cx_hash_key_str("key 1")), "val 1"), 0);
    EXPECT_EQ(strcmp((char *) cxMapGet(map, cx_hash_key_str("key 2")), "val 2"), 0);
    EXPECT_EQ(strcmp((char *) cxMapGet(map, cx_hash_key_str("key 3")), "val 3"), 0);
    EXPECT_EQ(strcmp((char *) cxMapGet(map, cx_hash_key_str("key 4")), "val 4"), 0);
    EXPECT_EQ(strcmp((char *) cxMapGet(map, cx_hash_key_str("key 5")), "val 5"), 0);
    EXPECT_EQ(strcmp((char *) cxMapGet(map, cx_hash_key_str("key 6")), "val 6"), 0);
    EXPECT_EQ(strcmp((char *) cxMapGet(map, cx_hash_key_str("key 7")), "val 7"), 0);

    cxMapDestroy(map);
    EXPECT_TRUE(allocator.verify());
}