add compile abi and bin

contract/mixer/BaseMerkleTree.sol

@@ -0,0 +1,66 @@
+// Copyright (c) 2015-2020 Clearmatics Technologies Ltd
+//
+// SPDX-License-Identifier: LGPL-3.0+
+
+pragma solidity ^0.5.0;
+
+// Adapted from: https://github.com/zcash-hackworks/babyzoe
+
+contract BaseMerkleTree {
+    // Depth of the merkle tree (should be set with the same depth set in the
+    // cpp prover)
+    uint256 constant DEPTH = 5;
+
+    // Number of leaves
+    uint256 constant MAX_NUM_LEAVES = 2**DEPTH;
+
+    // Number of nodes
+    uint constant MAX_NUM_NODES = (MAX_NUM_LEAVES * 2) - 1;
+
+    bytes32 constant DEFAULT_LEAF_VALUE = 0x0;
+
+    // Array containing the 2^(depth) leaves of the merkle tree.  We can switch
+    // the leaves to be of type bytes and not bytes32 to support digest of
+    // various size (eg: if we use different hash functions).  That way we'd
+    // have a merkle tree for any type of hash function (that can be implemented
+    // as a precompiled contract for instance)
+    //
+    // Leaves is a 2D array
+
+    // Sparse array of populated leaves of the merkle tree.  Unpopulated leaves
+    // have the DEFAULT_LEAF_VALUE.
+
+    bytes32[MAX_NUM_NODES] nodes;
+
+    // Number of leaves populated in `nodes`.
+    uint256 num_leaves;
+
+    // Debug only
+    event LogDebug(bytes32 message);
+
+    // Constructor
+    constructor(uint256 treeDepth) public {
+        require (
+            treeDepth == DEPTH,
+            "Invalid depth in BaseMerkleTree");
+    }
+
+    // Appends a commitment to the tree, and returns its address
+    function insert(bytes32 commitment) public {
+
+        // If this require fails => the merkle tree is full, we can't append
+        // leaves anymore.
+        require(
+            num_leaves < MAX_NUM_LEAVES,
+            "Merkle tree full: Cannot append anymore"
+        );
+
+        // Address of the next leaf is the current number of leaves (before
+        // insertion).  Compute the next index in the full set of nodes, and
+        // write.
+        uint256 next_address = num_leaves;
+        ++num_leaves;
+        uint256 next_entry_idx = (MAX_NUM_LEAVES - 1) + next_address;
+        nodes[next_entry_idx] = commitment;
+    }
+}