1 // Copyright 2014 Google Inc. All rights reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 // Sample code for encoder.cc.
16 //
17 // This is the code in README.md. It's here to make sure it actually builds
18 // and runs.
19
20 #include <cassert> // assert
21
22 #include "encoder.h"
23 #include "openssl_hash_impl.h"
24 #include "unix_kernel_rand_impl.h"
25
main(int argc,char ** argv)26 int main(int argc, char** argv) {
27 // Suppress unused variable warnings
28 (void) argc;
29 (void) argv;
30
31 FILE* fp = fopen("/dev/urandom", "r");
32 rappor::UnixKernelRand irr_rand(fp);
33
34 rappor::Deps deps(rappor::Md5, "client-secret", rappor::HmacSha256,
35 irr_rand);
36 rappor::Params params(32, // num_bits (k)
37 2, // num_hashes (h)
38 128, // num_cohorts (m)
39 0.25, // probability f for PRR
40 0.75, // probability p for IRR
41 0.5); // probability q for IRR
42
43 const char* encoder_id = "metric-name";
44 rappor::Encoder encoder(encoder_id, params, deps);
45
46 // Now use it to encode values. The 'out' value can be sent over the
47 // network.
48 rappor::Bits out;
49 assert(encoder.EncodeString("foo", &out)); // returns false on error
50 printf("'foo' encoded with RAPPOR: %0x, cohort %d\n", out, encoder.cohort());
51
52 // Raw bits
53 assert(encoder.EncodeBits(0x123, &out)); // returns false on error
54 printf("0x123 encoded with RAPPOR: %0x, cohort %d\n", out, encoder.cohort());
55 }
56
57