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      1 // Copyright (c) 2011 The LevelDB Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file. See the AUTHORS file for names of contributors.
      4 
      5 #include "util/coding.h"
      6 
      7 #include "util/testharness.h"
      8 
      9 namespace leveldb {
     10 
     11 class Coding { };
     12 
     13 TEST(Coding, Fixed32) {
     14   std::string s;
     15   for (uint32_t v = 0; v < 100000; v++) {
     16     PutFixed32(&s, v);
     17   }
     18 
     19   const char* p = s.data();
     20   for (uint32_t v = 0; v < 100000; v++) {
     21     uint32_t actual = DecodeFixed32(p);
     22     ASSERT_EQ(v, actual);
     23     p += sizeof(uint32_t);
     24   }
     25 }
     26 
     27 TEST(Coding, Fixed64) {
     28   std::string s;
     29   for (int power = 0; power <= 63; power++) {
     30     uint64_t v = static_cast<uint64_t>(1) << power;
     31     PutFixed64(&s, v - 1);
     32     PutFixed64(&s, v + 0);
     33     PutFixed64(&s, v + 1);
     34   }
     35 
     36   const char* p = s.data();
     37   for (int power = 0; power <= 63; power++) {
     38     uint64_t v = static_cast<uint64_t>(1) << power;
     39     uint64_t actual;
     40     actual = DecodeFixed64(p);
     41     ASSERT_EQ(v-1, actual);
     42     p += sizeof(uint64_t);
     43 
     44     actual = DecodeFixed64(p);
     45     ASSERT_EQ(v+0, actual);
     46     p += sizeof(uint64_t);
     47 
     48     actual = DecodeFixed64(p);
     49     ASSERT_EQ(v+1, actual);
     50     p += sizeof(uint64_t);
     51   }
     52 }
     53 
     54 // Test that encoding routines generate little-endian encodings
     55 TEST(Coding, EncodingOutput) {
     56   std::string dst;
     57   PutFixed32(&dst, 0x04030201);
     58   ASSERT_EQ(4, dst.size());
     59   ASSERT_EQ(0x01, static_cast<int>(dst[0]));
     60   ASSERT_EQ(0x02, static_cast<int>(dst[1]));
     61   ASSERT_EQ(0x03, static_cast<int>(dst[2]));
     62   ASSERT_EQ(0x04, static_cast<int>(dst[3]));
     63 
     64   dst.clear();
     65   PutFixed64(&dst, 0x0807060504030201ull);
     66   ASSERT_EQ(8, dst.size());
     67   ASSERT_EQ(0x01, static_cast<int>(dst[0]));
     68   ASSERT_EQ(0x02, static_cast<int>(dst[1]));
     69   ASSERT_EQ(0x03, static_cast<int>(dst[2]));
     70   ASSERT_EQ(0x04, static_cast<int>(dst[3]));
     71   ASSERT_EQ(0x05, static_cast<int>(dst[4]));
     72   ASSERT_EQ(0x06, static_cast<int>(dst[5]));
     73   ASSERT_EQ(0x07, static_cast<int>(dst[6]));
     74   ASSERT_EQ(0x08, static_cast<int>(dst[7]));
     75 }
     76 
     77 TEST(Coding, Varint32) {
     78   std::string s;
     79   for (uint32_t i = 0; i < (32 * 32); i++) {
     80     uint32_t v = (i / 32) << (i % 32);
     81     PutVarint32(&s, v);
     82   }
     83 
     84   const char* p = s.data();
     85   const char* limit = p + s.size();
     86   for (uint32_t i = 0; i < (32 * 32); i++) {
     87     uint32_t expected = (i / 32) << (i % 32);
     88     uint32_t actual;
     89     const char* start = p;
     90     p = GetVarint32Ptr(p, limit, &actual);
     91     ASSERT_TRUE(p != NULL);
     92     ASSERT_EQ(expected, actual);
     93     ASSERT_EQ(VarintLength(actual), p - start);
     94   }
     95   ASSERT_EQ(p, s.data() + s.size());
     96 }
     97 
     98 TEST(Coding, Varint64) {
     99   // Construct the list of values to check
    100   std::vector<uint64_t> values;
    101   // Some special values
    102   values.push_back(0);
    103   values.push_back(100);
    104   values.push_back(~static_cast<uint64_t>(0));
    105   values.push_back(~static_cast<uint64_t>(0) - 1);
    106   for (uint32_t k = 0; k < 64; k++) {
    107     // Test values near powers of two
    108     const uint64_t power = 1ull << k;
    109     values.push_back(power);
    110     values.push_back(power-1);
    111     values.push_back(power+1);
    112   }
    113 
    114   std::string s;
    115   for (size_t i = 0; i < values.size(); i++) {
    116     PutVarint64(&s, values[i]);
    117   }
    118 
    119   const char* p = s.data();
    120   const char* limit = p + s.size();
    121   for (size_t i = 0; i < values.size(); i++) {
    122     ASSERT_TRUE(p < limit);
    123     uint64_t actual;
    124     const char* start = p;
    125     p = GetVarint64Ptr(p, limit, &actual);
    126     ASSERT_TRUE(p != NULL);
    127     ASSERT_EQ(values[i], actual);
    128     ASSERT_EQ(VarintLength(actual), p - start);
    129   }
    130   ASSERT_EQ(p, limit);
    131 
    132 }
    133 
    134 TEST(Coding, Varint32Overflow) {
    135   uint32_t result;
    136   std::string input("\x81\x82\x83\x84\x85\x11");
    137   ASSERT_TRUE(GetVarint32Ptr(input.data(), input.data() + input.size(), &result)
    138               == NULL);
    139 }
    140 
    141 TEST(Coding, Varint32Truncation) {
    142   uint32_t large_value = (1u << 31) + 100;
    143   std::string s;
    144   PutVarint32(&s, large_value);
    145   uint32_t result;
    146   for (size_t len = 0; len < s.size() - 1; len++) {
    147     ASSERT_TRUE(GetVarint32Ptr(s.data(), s.data() + len, &result) == NULL);
    148   }
    149   ASSERT_TRUE(GetVarint32Ptr(s.data(), s.data() + s.size(), &result) != NULL);
    150   ASSERT_EQ(large_value, result);
    151 }
    152 
    153 TEST(Coding, Varint64Overflow) {
    154   uint64_t result;
    155   std::string input("\x81\x82\x83\x84\x85\x81\x82\x83\x84\x85\x11");
    156   ASSERT_TRUE(GetVarint64Ptr(input.data(), input.data() + input.size(), &result)
    157               == NULL);
    158 }
    159 
    160 TEST(Coding, Varint64Truncation) {
    161   uint64_t large_value = (1ull << 63) + 100ull;
    162   std::string s;
    163   PutVarint64(&s, large_value);
    164   uint64_t result;
    165   for (size_t len = 0; len < s.size() - 1; len++) {
    166     ASSERT_TRUE(GetVarint64Ptr(s.data(), s.data() + len, &result) == NULL);
    167   }
    168   ASSERT_TRUE(GetVarint64Ptr(s.data(), s.data() + s.size(), &result) != NULL);
    169   ASSERT_EQ(large_value, result);
    170 }
    171 
    172 TEST(Coding, Strings) {
    173   std::string s;
    174   PutLengthPrefixedSlice(&s, Slice(""));
    175   PutLengthPrefixedSlice(&s, Slice("foo"));
    176   PutLengthPrefixedSlice(&s, Slice("bar"));
    177   PutLengthPrefixedSlice(&s, Slice(std::string(200, 'x')));
    178 
    179   Slice input(s);
    180   Slice v;
    181   ASSERT_TRUE(GetLengthPrefixedSlice(&input, &v));
    182   ASSERT_EQ("", v.ToString());
    183   ASSERT_TRUE(GetLengthPrefixedSlice(&input, &v));
    184   ASSERT_EQ("foo", v.ToString());
    185   ASSERT_TRUE(GetLengthPrefixedSlice(&input, &v));
    186   ASSERT_EQ("bar", v.ToString());
    187   ASSERT_TRUE(GetLengthPrefixedSlice(&input, &v));
    188   ASSERT_EQ(std::string(200, 'x'), v.ToString());
    189   ASSERT_EQ("", input.ToString());
    190 }
    191 
    192 }  // namespace leveldb
    193 
    194 int main(int argc, char** argv) {
    195   return leveldb::test::RunAllTests();
    196 }
    197