8000 Containers: Add Containers memory dump test · Pagghiu/SaneCppLibraries@2019d98 · GitHub
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Containers: Add Containers memory dump test
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‎Libraries/Containers/Tests/GlobalsContainerTest.cpp

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Original file line numberDiff line numberDiff line change
@@ -4,6 +4,8 @@
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#include "../../Strings/String.h"
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#include "../../Testing/Testing.h"
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#include "../Vector.h"
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#include "../VectorMap.h"
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#include "../VectorSet.h"
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namespace SC
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{
@@ -19,9 +21,14 @@ struct SC::GlobalsContainerTest : public SC::TestCase
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{
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virtualGlobal();
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}
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if (test_section("virtual memory dump"))
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{
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virtualMemoryDump();
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}
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}
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void virtualGlobal();
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void virtualMemoryDump();
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};
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void SC::GlobalsContainerTest::virtualGlobal()
@@ -40,6 +47,85 @@ void SC::GlobalsContainerTest::virtualGlobal()
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Globals::pop(Globals::ThreadLocal);
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}
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void SC::GlobalsContainerTest::virtualMemoryDump()
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{
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//! [GlobalContainerVirtualMemoryDumpSnippet]
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// -----------------------------------------------------------------------------
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// Example showing how to dump and restore a complex struct to a flat buffer.
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// SC::Segment based containers use relative pointers to make this possible.
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// DO NOT use this approach when versioning is needed, that means needing to
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// de-serialize after adding, removing or moving fields in the structure.
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// In such cases consider using SC::SerializationBinary (versioned reflection).
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// -----------------------------------------------------------------------------
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struct NestedStruct
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{
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VectorMap<String, int> someMap;
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VectorSet<int> someSet;
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};
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struct ComplexStruct
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{
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Vector<String> someStrings;
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int someField = 0;
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String singleString;
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NestedStruct nestedStruct;
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};
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Buffer memoryDump;
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// Setup a Virtual Memory allocator with the max upper memory bound
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VirtualMemory virtualMemory;
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SC_TEST_EXPECT(virtualMemory.reserve(1024 * 1024)); // 1MB is enough here
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VirtualAllocator allocator = {virtualMemory};
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Globals globals = {allocator};
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// Make the allocator current before creating a ComplexStruct
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Globals::push(Globals::Global, globals);
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ComplexStruct& object = *allocator.create<ComplexStruct>();
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object.someField = 42;
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object.singleString = "ASDF";
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object.someStrings = {"First", "Second"};
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SC_TEST_EXPECT(object.nestedStruct.someSet.insert(213));
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SC_TEST_EXPECT(object.nestedStruct.someMap.insertIfNotExists({"1", 1}));
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// Save used bytes to memoryDump, checking that one page has been committed
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Span<const void> memory = {allocator.data(), allocator.size()};
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SC_TEST_EXPECT(virtualMemory.committedBytes == virtualMemory.getPageSize());
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SC_TEST_EXPECT(memory.sizeInBytes() < virtualMemory.getPageSize());
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SC_TEST_EXPECT(memory.data() == &object);
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SC_TEST_EXPECT((size_t(memoryDump.data()) % alignof(ComplexStruct)) == 0);
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Globals::pop(Globals::Global);
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// Dump AFTER Globals::pop, using default allocator, and release virtual memory
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SC_TEST_EXPECT(memoryDump.append(memory));
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SC_TEST_EXPECT(virtualMemory.release());
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// -----------------------------------------------------------------------------
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// Obtain a read-only view over ComplexStruct by re-interpreting the memory dump
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// NOTE: There's no need to call ComplexStruct destructor at end of scope
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// WARN: Using a different struct type or layout than the dumped one is UB
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// -----------------------------------------------------------------------------
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const Span<const void> span = memoryDump.toSpanConst();
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const ComplexStruct& readonly = *span.start_lifetime_as<const ComplexStruct>();
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SC_TEST_EXPECT(readonly.someField == 42);
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SC_TEST_EXPECT(readonly.singleString == "ASDF");
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SC_TEST_EXPECT(readonly.someStrings[0] == "First");
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SC_TEST_EXPECT(readonly.someStrings[1] == "Second");
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SC_TEST_EXPECT(readonly.someStrings.size() == 2);
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SC_TEST_EXPECT(readonly.nestedStruct.someSet.size() == 1);
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SC_TEST_EXPECT(readonly.nestedStruct.someSet.contains(213));
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SC_TEST_EXPECT(*readonly.nestedStruct.someMap.get("1") == 1);
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// -----------------------------------------------------------------------------
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// To modify the struct again, copy the read-only view to a new object.
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// A Fixed or Virtual allocator can be used here to group sparse allocations in
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// a nice single contiguous buffer, before dumping it again to disk or network.
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// -----------------------------------------------------------------------------
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ComplexStruct modifiable = readonly;
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SC_TEST_EXPECT(modifiable.someStrings[0] == "First");
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modifiable.someStrings[0] = "First modified";
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SC_TEST_EXPECT(modifiable.someStrings[0] == "First modified");
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//! [GlobalContainerVirtualMemoryDumpSnippet]
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}
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namespace SC
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{
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void runGlobalsContainerTest(SC::TestReport& report) { GlobalsContainerTest test(report); }

‎Libraries/Foundation/Globals.h

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@@ -30,6 +30,9 @@ struct SC::GlobalSettings
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///
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/// Example (Virtual Allocator):
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/// \snippet Libraries/Foundation/Tests/GlobalsTest.cpp GlobalsSnippetVirtual
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///
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/// Example (Memory dump):
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/// \snippet Libraries/Containers/Tests/GlobalsContainerTest.cpp GlobalContainerVirtualMemoryDumpSnippet
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struct SC::Globals
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{
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enum Type

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