Auto merge of #2670 - arielgabizon:lowmemprover, r=daira

Low memory prover

This PR integrates @ebfull 's low memory changes:  https://github.com/zcash/zcash/pull/2243/commits
on top of @str4d 's work bringing in libsnark as a subtree
4699d0eb36

src/test/rpc_wallet_tests.cpp

@@ -1175,7 +1175,7 @@ BOOST_AUTO_TEST_CASE(rpc_z_sendmany_internals)
         try {
             proxy.perform_joinsplit(info);
         } catch (const std::runtime_error & e) {
-            BOOST_CHECK( string(e.what()).find("JoinSplit verifying key not loaded")!= string::npos);
+            BOOST_CHECK( string(e.what()).find("error verifying joinsplit")!= string::npos);
         }
     }
 
@@ -1372,7 +1372,7 @@ BOOST_AUTO_TEST_CASE(rpc_z_shieldcoinbase_internals)
         try {
             proxy.perform_joinsplit(info);
         } catch (const std::runtime_error & e) {
-            BOOST_CHECK( string(e.what()).find("JoinSplit verifying key not loaded")!= string::npos);
+            BOOST_CHECK( string(e.what()).find("error verifying joinsplit")!= string::npos);
         }
     }
 

src/test/test_bitcoin.cpp

@@ -30,20 +30,30 @@ ZCJoinSplit *pzcashParams;
 extern bool fPrintToConsole;
 extern void noui_connect();
 
+JoinSplitTestingSetup::JoinSplitTestingSetup()
+{
+    boost::filesystem::path pk_path = ZC_GetParamsDir() / "sprout-proving.key";
+    boost::filesystem::path vk_path = ZC_GetParamsDir() / "sprout-verifying.key";
+    pzcashParams = ZCJoinSplit::Prepared(vk_path.string(), pk_path.string());
+}
+
+JoinSplitTestingSetup::~JoinSplitTestingSetup()
+{
+    delete pzcashParams;
+}
+
 BasicTestingSetup::BasicTestingSetup()
 {
-        assert(init_and_check_sodium() != -1);
-        ECC_Start();
-        pzcashParams = ZCJoinSplit::Unopened();
-        SetupEnvironment();
-        fPrintToDebugLog = false; // don't want to write to debug.log file
-        fCheckBlockIndex = true;
-        SelectParams(CBaseChainParams::MAIN);
+    assert(init_and_check_sodium() != -1);
+    ECC_Start();
+    SetupEnvironment();
+    fPrintToDebugLog = false; // don't want to write to debug.log file
+    fCheckBlockIndex = true;
+    SelectParams(CBaseChainParams::MAIN);
 }
 BasicTestingSetup::~BasicTestingSetup()
 {
-        ECC_Stop();
-        delete pzcashParams;
+    ECC_Stop();
 }
 
 TestingSetup::TestingSetup()

src/test/test_bitcoin.h

@@ -17,11 +17,17 @@ struct BasicTestingSetup {
     ~BasicTestingSetup();
 };
 
+// Setup w.r.t. zk-SNARK API
+struct JoinSplitTestingSetup: public BasicTestingSetup {
+    JoinSplitTestingSetup();
+    ~JoinSplitTestingSetup();
+};
+
 /** Testing setup that configures a complete environment.
  * Included are data directory, coins database, script check threads
  * and wallet (if enabled) setup.
  */
-struct TestingSetup: public BasicTestingSetup {
+struct TestingSetup: public JoinSplitTestingSetup {
     CCoinsViewDB *pcoinsdbview;
     boost::filesystem::path pathTemp;
     boost::thread_group threadGroup;

src/test/transaction_tests.cpp

@@ -6,6 +6,7 @@
 #include "data/tx_valid.json.h"
 #include "test/test_bitcoin.h"
 
+#include "init.h"
 #include "clientversion.h"
 #include "consensus/validation.h"
 #include "core_io.h"
@@ -85,7 +86,7 @@ string FormatScriptFlags(unsigned int flags)
     return ret.substr(0, ret.size() - 1);
 }
 
-BOOST_FIXTURE_TEST_SUITE(transaction_tests, BasicTestingSetup)
+BOOST_FIXTURE_TEST_SUITE(transaction_tests, JoinSplitTestingSetup)
 
 BOOST_AUTO_TEST_CASE(tx_valid)
 {
@@ -326,9 +327,6 @@ BOOST_AUTO_TEST_CASE(test_basic_joinsplit_verification)
     // Also, it's generally libzcash's job to ensure the
     // integrity of the scheme through its own tests.
 
-    // construct the r1cs keypair
-    auto p = ZCJoinSplit::Generate();
-
     // construct a merkle tree
     ZCIncrementalMerkleTree merkleTree;
 
@@ -362,8 +360,8 @@ BOOST_AUTO_TEST_CASE(test_basic_joinsplit_verification)
     auto verifier = libzcash::ProofVerifier::Strict();
 
     {
-        JSDescription jsdesc(*p, pubKeyHash, rt, inputs, outputs, 0, 0);
-        BOOST_CHECK(jsdesc.Verify(*p, verifier, pubKeyHash));
+        JSDescription jsdesc(*pzcashParams, pubKeyHash, rt, inputs, outputs, 0, 0);
+        BOOST_CHECK(jsdesc.Verify(*pzcashParams, verifier, pubKeyHash));
 
         CDataStream ss(SER_DISK, CLIENT_VERSION);
         ss << jsdesc;
@@ -372,20 +370,20 @@ BOOST_AUTO_TEST_CASE(test_basic_joinsplit_verification)
         ss >> jsdesc_deserialized;
 
         BOOST_CHECK(jsdesc_deserialized == jsdesc);
-        BOOST_CHECK(jsdesc_deserialized.Verify(*p, verifier, pubKeyHash));
+        BOOST_CHECK(jsdesc_deserialized.Verify(*pzcashParams, verifier, pubKeyHash));
     }
 
     {
         // Ensure that the balance equation is working.
-        BOOST_CHECK_THROW(JSDescription(*p, pubKeyHash, rt, inputs, outputs, 10, 0), std::invalid_argument);
-        BOOST_CHECK_THROW(JSDescription(*p, pubKeyHash, rt, inputs, outputs, 0, 10), std::invalid_argument);
+        BOOST_CHECK_THROW(JSDescription(*pzcashParams, pubKeyHash, rt, inputs, outputs, 10, 0), std::invalid_argument);
+        BOOST_CHECK_THROW(JSDescription(*pzcashParams, pubKeyHash, rt, inputs, outputs, 0, 10), std::invalid_argument);
     }
 
     {
         // Ensure that it won't verify if the root is changed.
-        auto test = JSDescription(*p, pubKeyHash, rt, inputs, outputs, 0, 0);
+        auto test = JSDescription(*pzcashParams, pubKeyHash, rt, inputs, outputs, 0, 0);
         test.anchor = GetRandHash();
-        BOOST_CHECK(!test.Verify(*p, verifier, pubKeyHash));
+        BOOST_CHECK(!test.Verify(*pzcashParams, verifier, pubKeyHash));
     }
 }