detect gas limit for a node (#545)

src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumUpstreamSettingsDetector.kt

@@ -11,6 +11,7 @@ import io.emeraldpay.dshackle.upstream.Upstream
 import io.emeraldpay.dshackle.upstream.rpcclient.ListParams
 import reactor.core.publisher.Flux
 import reactor.core.publisher.Mono
+import kotlin.text.toBigInteger
 
 const val ZERO_ADDRESS = "0x0000000000000000000000000000000000000000"
 
@@ -24,6 +25,7 @@ class EthereumUpstreamSettingsDetector(
         return Flux.merge(
             detectNodeType(),
             detectArchiveNode(),
+            detectGasLabels(),
         )
     }
 
@@ -43,6 +45,50 @@ class EthereumUpstreamSettingsDetector(
         return version
     }
 
+    /**
+     * We use this smart contract to get gas limit
+     * pragma solidity ^0.8.0;
+     *
+     * contract GasChecker {
+     *
+     *     // Function to return the amount of gas left
+     *     function getGasLeft() external view returns (uint256) {
+     *         return gasleft();
+     *     }
+     * }
+     *
+     */
+    private fun detectGasLabels(): Flux<Pair<String, String>> {
+        return upstream.getIngressReader().read(
+            ChainRequest(
+                "eth_call",
+                ListParams(
+                    mapOf(
+                        "to" to "0x53Daa71B04d589429f6d3DF52db123913B818F22",
+                        "data" to "0x51be4eaa",
+                    ),
+                    "latest",
+                    mapOf(
+                        "0x53Daa71B04d589429f6d3DF52db123913B818F22" to mapOf(
+                            "code" to "0x6080604052348015600e575f80fd5b50600436106026575f3560e01c806351be4eaa14602a575b5f80fd5b60306044565b604051603b91906061565b60405180910390f35b5f5a905090565b5f819050919050565b605b81604b565b82525050565b5f60208201905060725f8301846054565b9291505056fea2646970667358221220a85b088da3911ea743505594ac7cfdd1a65865de64499ee1f3c6bd9cdad4552364736f6c634300081a0033",
+                        ),
+                    ),
+                ),
+            ),
+        ).flatMap {
+            it.requireResult()
+        }.flatMapMany {
+            val gaslimit = String(it).drop(3).dropLast(1).toBigInteger(16) + (21180).toBigInteger()
+            val labels = mutableListOf(Pair("gas-limit", gaslimit.toString(10)))
+            if (gaslimit >= (600_000_000).toBigInteger()) {
+                labels.add(Pair("extra_gas_limit", "600000000"))
+            }
+            Flux.fromIterable(labels)
+        }.onErrorResume {
+            Flux.empty()
+        }
+    }
+
     private fun detectArchiveNode(): Mono<Pair<String, String>> {
         if (upstream.getLabels().firstOrNull { it.getOrDefault("archive", "") == "false" } != null) {
             return Mono.empty()

src/test/groovy/io/emeraldpay/dshackle/upstream/ethereum/EthereumUpstreamSettingsDetectorSpec.groovy

@@ -25,6 +25,16 @@ class EthereumUpstreamSettingsDetectorSpec extends Specification {
                     answer("eth_blockNumber", [], "0x10df3e5")
                     answer("eth_getBalance", ["0x0000000000000000000000000000000000000000", "0x10dccd5"], "")
                     answer("eth_getBalance", ["0x0000000000000000000000000000000000000000", "0x2710"], "")
+                    answer("eth_call", [[
+                            "to": "0x53Daa71B04d589429f6d3DF52db123913B818F22",
+                            "data": "0x51be4eaa",
+                    ],
+                            "latest",
+                            [
+                                    "0x53Daa71B04d589429f6d3DF52db123913B818F22": [
+                                            "code": "0x6080604052348015600e575f80fd5b50600436106026575f3560e01c806351be4eaa14602a575b5f80fd5b60306044565b604051603b91906061565b60405180910390f35b5f5a905090565b5f819050919050565b605b81604b565b82525050565b5f60208201905060725f8301846054565b9291505056fea2646970667358221220a85b088da3911ea743505594ac7cfdd1a65865de64499ee1f3c6bd9cdad4552364736f6c634300081a0033",
+                                    ],
+                            ]], "0x2fa9dc4")
                 }
         )
         def detector = new EthereumUpstreamSettingsDetector(up, Chain.ETHEREUM__MAINNET)
@@ -36,7 +46,8 @@ class EthereumUpstreamSettingsDetectorSpec extends Specification {
             .expectNext(
                     new Pair<String, String>("client_type", clientType),
                     new Pair<String, String>("client_version", version),
-                    new Pair<String, String>("archive", "true")
+                    new Pair<String, String>("archive", "true"),
+                    new Pair<String, String>("gas-limit", "50000000")
             )
             .expectComplete()
             .verify(Duration.ofSeconds(1))
@@ -76,7 +87,7 @@ class EthereumUpstreamSettingsDetectorSpec extends Specification {
     def "Only default label"() {
         setup:
         def up = Mock(DefaultUpstream) {
-            4 * getIngressReader() >> Mock(Reader) {
+            5 * getIngressReader() >> Mock(Reader) {
                 1 * read(new ChainRequest("web3_clientVersion", new ListParams())) >>
                         Mono.just(new ChainResponse('no/v1.19.3+e8ac1da4/linux-x64/dotnet7.0.8'.getBytes(), null))
                 1 * read(new ChainRequest("eth_blockNumber", new ListParams())) >>
@@ -85,6 +96,18 @@ class EthereumUpstreamSettingsDetectorSpec extends Specification {
                         Mono.error(new RuntimeException())
                 1 * read(new ChainRequest("eth_getBalance", new ListParams(["0x0000000000000000000000000000000000000000", "0x2710"]))) >>
                         Mono.just(new ChainResponse("".getBytes(), null))
+                1 * read(new ChainRequest("eth_call", new ListParams([
+                                "to": "0x53Daa71B04d589429f6d3DF52db123913B818F22",
+                                "data": "0x51be4eaa",
+                        ],
+                        "latest",
+                        [
+                                "0x53Daa71B04d589429f6d3DF52db123913B818F22": [
+                                        "code": "0x6080604052348015600e575f80fd5b50600436106026575f3560e01c806351be4eaa14602a575b5f80fd5b60306044565b604051603b91906061565b60405180910390f35b5f5a905090565b5f819050919050565b605b81604b565b82525050565b5f60208201905060725f8301846054565b9291505056fea2646970667358221220a85b088da3911ea743505594ac7cfdd1a65865de64499ee1f3c6bd9cdad4552364736f6c634300081a0033",
+                                ],
+                        ],
+                ))) >>
+                        Mono.just(new ChainResponse("".getBytes(), null))
             }
             getLabels() >> []
         }