Add arena debug visualization tool

CMakeLists.txt

@@ -82,6 +82,14 @@ target_link_libraries(bench_parser_comparison nanobench weaseljson test_data
                       nlohmann_json::nlohmann_json)
 target_include_directories(bench_parser_comparison PRIVATE src)
 
+# Debug tools
+add_executable(debug_arena tools/debug_arena.cpp src/commit_request.cpp)
+target_link_libraries(debug_arena weaseljson)
+target_include_directories(debug_arena PRIVATE src)
+
+add_executable(test_multi_block test_multi_block.cpp)
+target_include_directories(test_multi_block PRIVATE src)
+
 add_test(NAME arena_allocator_tests COMMAND test_arena_allocator)
 add_test(NAME commit_request_tests COMMAND test_commit_request)
 add_test(NAME arena_allocator_benchmarks COMMAND bench_arena_allocator)

benchmarks/bench_commit_request.cpp

@@ -92,26 +92,6 @@ int main() {
         });
   }
 
-  // Memory allocation efficiency benchmarks
-  auto memory_bench = ankerl::nanobench::Bench()
-                          .title("CommitRequest Memory Usage")
-                          .unit("allocation")
-                          .warmup(50);
-
-  // Different arena sizes
-  for (size_t arena_size : {1024, 4096, 16384, 65536}) {
-    memory_bench.run(
-        "Arena size " + std::to_string(arena_size) + " bytes", [&] {
-          CommitRequest request(arena_size);
-          std::string mutable_json = COMPLEX_JSON;
-          bool result =
-              request.parse_json(mutable_json.data(), mutable_json.size());
-          ankerl::nanobench::doNotOptimizeAway(result);
-          ankerl::nanobench::doNotOptimizeAway(request.total_allocated());
-          ankerl::nanobench::doNotOptimizeAway(request.used_bytes());
-        });
-  }
-
   // Reset and reuse benchmarks
   auto reuse_bench = ankerl::nanobench::Bench()
                          .title("CommitRequest Reset and Reuse")

benchmarks/bench_parser_comparison.cpp

@@ -242,7 +242,7 @@ int main() {
                           .minEpochIterations(200);
 
   memory_bench.run("WeaselDB Parser (arena allocation)", [&] {
-    CommitRequest request(4096); // 4KB arena
+    CommitRequest request;
     std::string mutable_json = COMPLEX_JSON;
     bool result = request.parse_json(mutable_json.data(), mutable_json.size());
     ankerl::nanobench::doNotOptimizeAway(result);

src/arena_allocator.hpp

@@ -4,6 +4,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstdlib>
+#include <cstring>
 #include <iomanip>
 #include <iostream>
 #include <new>
@@ -369,6 +370,181 @@ public:
     return current_block_ ? current_block_->block_count : 0;
   }
 
+  /**
+   * @brief Debug function to find all intra-arena pointers.
+   *
+   * Scans all used memory in the arena for 64-bit aligned values that could be
+   * pointers to locations within the arena itself. This is useful for
+   * understanding memory references and potential data structures.
+   *
+   * @return Vector of PointerInfo structs containing source and target
+   * addresses
+   */
+  struct PointerInfo {
+    const void *source_addr;    ///< Address where the pointer was found
+    size_t source_block_number; ///< Block number containing the source
+    size_t source_offset;       ///< Offset within the source block
+    const void *target_addr;    ///< Address the pointer points to
+    size_t target_block_number; ///< Block number containing the target
+    size_t target_offset;       ///< Offset within the target block
+
+    PointerInfo(const void *src, size_t src_block, size_t src_offset,
+                const void *target, size_t target_block, size_t target_offset)
+        : source_addr(src), source_block_number(src_block),
+          source_offset(src_offset), target_addr(target),
+          target_block_number(target_block), target_offset(target_offset) {}
+  };
+
+  std::vector<PointerInfo> find_intra_arena_pointers() const {
+    std::vector<PointerInfo> pointers;
+
+    if (!current_block_) {
+      return pointers;
+    }
+
+    // Build list of blocks from current to first
+    std::vector<Block *> blocks;
+    Block *block = current_block_;
+    while (block) {
+      blocks.push_back(block);
+      block = block->prev;
+    }
+
+    // Helper function to check if a pointer value points within the used area
+    // of any block
+    auto is_intra_arena_pointer = [&blocks,
+                                   this](uint64_t pointer_value) -> bool {
+      for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
+        Block *b = blocks[block_idx];
+        uintptr_t block_start = reinterpret_cast<uintptr_t>(b->data());
+
+        // Calculate used bytes in this specific block
+        size_t block_used;
+        if (block_idx == 0) {
+          // Current block - use current_offset_
+          block_used = current_offset_;
+        } else {
+          // Previous blocks are fully used
+          block_used = b->size;
+        }
+
+        uintptr_t block_used_end = block_start + block_used;
+
+        // Check if pointer falls within the used area of this block
+        if (pointer_value >= block_start && pointer_value < block_used_end) {
+          return true;
+        }
+      }
+      return false;
+    };
+
+    // Scan each block for pointers
+    for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
+      Block *b = blocks[block_idx];
+      const char *data = b->data();
+
+      // Calculate used bytes in this specific block
+      size_t block_used;
+      if (block_idx == 0) {
+        // Current block - use current_offset_
+        block_used = current_offset_;
+      } else {
+        // Previous blocks are fully used
+        block_used = b->size;
+      }
+
+      // Scan for 64-bit aligned pointers
+      for (size_t offset = 0; offset + sizeof(uint64_t) <= block_used;
+           offset += sizeof(uint64_t)) {
+        uint64_t potential_pointer;
+        std::memcpy(&potential_pointer, data + offset,
+                    sizeof(potential_pointer));
+
+        // Check if this value points within the used area of any block
+        if (is_intra_arena_pointer(potential_pointer)) {
+          // Find target location within arena
+          auto target_location = find_address_location(
+              reinterpret_cast<const void *>(potential_pointer));
+
+          pointers.emplace_back(
+              data + offset,             // source address
+              blocks.size() - block_idx, // source block number (1-based)
+              offset,                    // source offset in block
+              reinterpret_cast<const void *>(
+                  potential_pointer), // target address
+              target_location.found ? target_location.block_number
+                                    : 0, // target block number
+              target_location.found ? target_location.offset_in_block
+                                    : 0 // target offset
+          );
+        }
+      }
+    }
+
+    return pointers;
+  }
+
+  /**
+   * @brief Find which block and offset a given address belongs to.
+   *
+   * @param addr The address to locate within the arena
+   * @return PointerInfo with block number and offset, or invalid info if not
+   * found
+   */
+  struct AddressLocation {
+    size_t block_number;
+    size_t offset_in_block;
+    bool found;
+
+    AddressLocation() : block_number(0), offset_in_block(0), found(false) {}
+    AddressLocation(size_t block, size_t offset)
+        : block_number(block), offset_in_block(offset), found(true) {}
+  };
+
+  AddressLocation find_address_location(const void *addr) const {
+    if (!current_block_ || !addr) {
+      return AddressLocation();
+    }
+
+    uintptr_t target_addr = reinterpret_cast<uintptr_t>(addr);
+
+    // Build list of blocks from current to first
+    std::vector<Block *> blocks;
+    Block *block = current_block_;
+    while (block) {
+      blocks.push_back(block);
+      block = block->prev;
+    }
+
+    // Check each block to see if the address falls within its used area
+    for (size_t block_idx = 0; block_idx < blocks.size(); ++block_idx) {
+      Block *b = blocks[block_idx];
+      uintptr_t block_start = reinterpret_cast<uintptr_t>(b->data());
+
+      // Calculate used bytes in this specific block
+      size_t block_used;
+      if (block_idx == 0) {
+        // Current block - use current_offset_
+        block_used = current_offset_;
+      } else {
+        // Previous blocks are fully used
+        block_used = b->size;
+      }
+
+      uintptr_t block_used_end = block_start + block_used;
+
+      // Check if address falls within the used area of this block
+      if (target_addr >= block_start && target_addr < block_used_end) {
+        return AddressLocation(
+            blocks.size() - block_idx, // block number (1-based)
+            target_addr - block_start  // offset within block
+        );
+      }
+    }
+
+    return AddressLocation(); // Not found
+  }
+
   /**
    * @brief Debug function to visualize the arena's layout and contents.
    *

src/commit_request.hpp

@@ -129,9 +129,8 @@ public:
    * @brief Construct a new CommitRequest with the given initial arena size.
    * @param arena_size Initial size for the arena allocator
    */
-  explicit CommitRequest(size_t arena_size = 4096)
+  explicit CommitRequest()
-      : arena_(arena_size),
+      : arena_(), preconditions_(ArenaStlAllocator<Precondition>(&arena_)),
-        preconditions_(ArenaStlAllocator<Precondition>(&arena_)),
         operations_(ArenaStlAllocator<Operation>(&arena_)),
         parser_context_(&arena_) {}
 

tools/debug_arena.cpp

@@ -0,0 +1,389 @@
+#include "commit_request.hpp"
+#include <cstring>
+#include <fstream>
+#include <iomanip>
+#include <iostream>
+#include <sstream>
+#include <unordered_set>
+#include <vector>
+
+struct ArenaDebugger {
+  const CommitRequest &commit_request;
+  const ArenaAllocator &arena;
+  std::unordered_set<const void *> referenced_addresses;
+
+  explicit ArenaDebugger(const CommitRequest &cr)
+      : commit_request(cr), arena(cr.arena()) {}
+
+  void analyze_references() {
+    // Track all string_view data pointers from the parsed commit request
+    if (commit_request.request_id().has_value()) {
+      add_reference(commit_request.request_id()->data(),
+                    commit_request.request_id()->size());
+    }
+
+    add_reference(commit_request.leader_id().data(),
+                  commit_request.leader_id().size());
+
+    for (const auto &precond : commit_request.preconditions()) {
+      add_reference(precond.begin.data(), precond.begin.size());
+      add_reference(precond.end.data(), precond.end.size());
+    }
+
+    for (const auto &op : commit_request.operations()) {
+      add_reference(op.param1.data(), op.param1.size());
+      add_reference(op.param2.data(), op.param2.size());
+    }
+  }
+
+  void add_reference(const char *ptr, size_t size) {
+    if (ptr && size > 0) {
+      referenced_addresses.insert(ptr);
+      // Also add end pointer to mark the range
+      referenced_addresses.insert(ptr + size - 1);
+    }
+  }
+
+  void visualize_arena() {
+    std::cout << "=== Arena Visualization Debug Tool ===" << std::endl;
+    std::cout << "Analyzing commit request and arena memory layout"
+              << std::endl;
+    std::cout << std::endl;
+
+    // First, analyze what's referenced
+    analyze_references();
+
+    // Print basic arena statistics
+    std::cout << "Arena Statistics:" << std::endl;
+    std::cout << "- Total allocated: " << arena.total_allocated() << " bytes"
+              << std::endl;
+    std::cout << "- Currently used: " << arena.used_bytes() << " bytes"
+              << std::endl;
+    std::cout << "- Number of blocks: " << arena.num_blocks() << " blocks"
+              << std::endl;
+    std::cout << "- Referenced addresses: " << referenced_addresses.size()
+              << std::endl;
+    std::cout << std::endl;
+
+    // Use the arena's debug_dump with content visualization
+    std::cout << "Raw Arena Memory Layout:" << std::endl;
+    arena.debug_dump(std::cout, true, true, 1024);
+
+    std::cout << std::endl;
+    std::cout << "=== Pointer Analysis ===" << std::endl;
+
+    // Scan for potential pointers in arena memory using the arena's built-in
+    // method
+    scan_arena_pointers();
+
+    std::cout << std::endl;
+    std::cout << "=== Referenced Memory Regions ===" << std::endl;
+    visualize_referenced_data();
+  }
+
+private:
+  void scan_arena_pointers() {
+    std::cout << "Scanning all used arena memory for 64-bit aligned pointers..."
+              << std::endl;
+
+    // Use the arena's comprehensive pointer scanning method
+    auto pointers = arena.find_intra_arena_pointers();
+
+    std::cout << "Arena memory scan complete:" << std::endl;
+    std::cout << "- Total scanned: " << arena.used_bytes() << " bytes across "
+              << arena.num_blocks() << " blocks" << std::endl;
+    std::cout << "- Intra-arena pointers found: " << pointers.size()
+              << std::endl;
+
+    if (pointers.empty()) {
+      std::cout << "No intra-arena pointers detected." << std::endl;
+      return;
+    }
+
+    std::cout << std::endl;
+    std::cout << "Detected pointers:" << std::endl;
+
+    for (size_t i = 0; i < pointers.size(); ++i) {
+      const auto &ptr_info = pointers[i];
+
+      std::cout << "Pointer #" << (i + 1) << ":" << std::endl;
+      std::cout << "  Source: " << ptr_info.source_addr << " (Block #"
+                << ptr_info.source_block_number << ", offset +0x" << std::hex
+                << ptr_info.source_offset << std::dec << ")" << std::endl;
+      std::cout << "  Target: " << ptr_info.target_addr << " (Block #"
+                << ptr_info.target_block_number << ", offset +0x" << std::hex
+                << ptr_info.target_offset << std::dec << ")" << std::endl;
+
+      // Try to identify what this pointer might be pointing to
+      identify_pointer_target(ptr_info.target_addr);
+
+      std::cout << std::endl;
+    }
+  }
+
+  void identify_pointer_target(const void *target_addr) {
+    // Check if this target address matches any of our known string data
+    std::cout << "  Points to: ";
+
+    bool found_match = false;
+
+    // Check request_id
+    if (commit_request.request_id().has_value()) {
+      const auto &req_id = *commit_request.request_id();
+      if (target_addr >= req_id.data() &&
+          target_addr < req_id.data() + req_id.size()) {
+        std::cout << "request_id string";
+        found_match = true;
+      }
+    }
+
+    // Check leader_id
+    if (!found_match) {
+      const auto &leader_id = commit_request.leader_id();
+      if (target_addr >= leader_id.data() &&
+          target_addr < leader_id.data() + leader_id.size()) {
+        std::cout << "leader_id string";
+        found_match = true;
+      }
+    }
+
+    // Check preconditions
+    if (!found_match) {
+      for (size_t i = 0; i < commit_request.preconditions().size(); ++i) {
+        const auto &precond = commit_request.preconditions()[i];
+
+        if (!precond.begin.empty() && target_addr >= precond.begin.data() &&
+            target_addr < precond.begin.data() + precond.begin.size()) {
+          std::cout << "precondition[" << i << "].begin string";
+          found_match = true;
+          break;
+        }
+
+        if (!precond.end.empty() && target_addr >= precond.end.data() &&
+            target_addr < precond.end.data() + precond.end.size()) {
+          std::cout << "precondition[" << i << "].end string";
+          found_match = true;
+          break;
+        }
+      }
+    }
+
+    // Check operations
+    if (!found_match) {
+      for (size_t i = 0; i < commit_request.operations().size(); ++i) {
+        const auto &op = commit_request.operations()[i];
+
+        if (!op.param1.empty() && target_addr >= op.param1.data() &&
+            target_addr < op.param1.data() + op.param1.size()) {
+          std::cout << "operation[" << i << "].param1 string";
+          found_match = true;
+          break;
+        }
+
+        if (!op.param2.empty() && target_addr >= op.param2.data() &&
+            target_addr < op.param2.data() + op.param2.size()) {
+          std::cout << "operation[" << i << "].param2 string";
+          found_match = true;
+          break;
+        }
+      }
+    }
+
+    if (!found_match) {
+      std::cout << "unknown arena data";
+    }
+
+    std::cout << std::endl;
+  }
+
+  std::string_view find_string_view_for_data(const char *data) {
+    if (commit_request.request_id().has_value() &&
+        commit_request.request_id()->data() == data) {
+      return *commit_request.request_id();
+    }
+
+    if (commit_request.leader_id().data() == data) {
+      return commit_request.leader_id();
+    }
+
+    for (const auto &precond : commit_request.preconditions()) {
+      if (precond.begin.data() == data)
+        return precond.begin;
+      if (precond.end.data() == data)
+        return precond.end;
+    }
+
+    for (const auto &op : commit_request.operations()) {
+      if (op.param1.data() == data)
+        return op.param1;
+      if (op.param2.data() == data)
+        return op.param2;
+    }
+
+    return {};
+  }
+
+  void visualize_referenced_data() {
+    std::cout << "Visualizing parsed commit request data references:"
+              << std::endl;
+    std::cout << std::endl;
+
+    // Show request_id
+    if (commit_request.request_id().has_value()) {
+      std::cout << "request_id: ";
+      visualize_string_data(*commit_request.request_id());
+    }
+
+    // Show leader_id
+    std::cout << "leader_id: ";
+    visualize_string_data(commit_request.leader_id());
+
+    // Show read_version
+    std::cout << "read_version: " << commit_request.read_version() << std::endl;
+
+    // Show preconditions
+    std::cout << "preconditions (" << commit_request.preconditions().size()
+              << "):" << std::endl;
+    for (size_t i = 0; i < commit_request.preconditions().size(); ++i) {
+      const auto &precond = commit_request.preconditions()[i];
+      std::cout << "  [" << i
+                << "] type: " << precondition_type_to_string(precond.type)
+                << ", version: " << precond.version << std::endl;
+      std::cout << "      begin: ";
+      visualize_string_data(precond.begin, "      ");
+      std::cout << "      end:   ";
+      visualize_string_data(precond.end, "      ");
+    }
+
+    // Show operations
+    std::cout << "operations (" << commit_request.operations().size()
+              << "):" << std::endl;
+    for (size_t i = 0; i < commit_request.operations().size(); ++i) {
+      const auto &op = commit_request.operations()[i];
+      std::cout << "  [" << i << "] type: " << operation_type_to_string(op.type)
+                << std::endl;
+      std::cout << "      param1: ";
+      visualize_string_data(op.param1, "      ");
+      std::cout << "      param2: ";
+      visualize_string_data(op.param2, "      ");
+    }
+  }
+
+  void visualize_string_data(std::string_view sv,
+                             const std::string &indent = "") {
+    if (sv.empty()) {
+      std::cout << "(empty)" << std::endl;
+      return;
+    }
+
+    const char *data = sv.data();
+    size_t size = sv.size();
+
+    std::cout << "\"" << sv << "\" @ " << static_cast<const void *>(data)
+              << " [" << size << " bytes]";
+
+    if (referenced_addresses.count(data)) {
+      std::cout << " (REFERENCED)";
+    }
+
+    std::cout << std::endl;
+
+    // Show hex dump of the string data
+    if (size > 0 && size <= 64) { // Only show hex for reasonable sizes
+      std::cout << indent << "Hex: ";
+      for (size_t i = 0; i < size; ++i) {
+        unsigned char byte = static_cast<unsigned char>(data[i]);
+        std::cout << std::hex << std::setfill('0') << std::setw(2)
+                  << static_cast<unsigned int>(byte) << std::dec;
+        if ((i + 1) % 4 == 0 && i < size - 1)
+          std::cout << " ";
+      }
+      std::cout << std::endl;
+    }
+  }
+
+  const char *precondition_type_to_string(Precondition::Type type) {
+    switch (type) {
+    case Precondition::Type::PointRead:
+      return "point_read";
+    case Precondition::Type::RangeRead:
+      return "range_read";
+    default:
+      return "unknown";
+    }
+  }
+
+  const char *operation_type_to_string(Operation::Type type) {
+    switch (type) {
+    case Operation::Type::Write:
+      return "write";
+    case Operation::Type::Delete:
+      return "delete";
+    case Operation::Type::RangeDelete:
+      return "range_delete";
+    default:
+      return "unknown";
+    }
+  }
+};
+
+int main(int argc, char *argv[]) {
+  if (argc != 2) {
+    std::cerr << "Usage: " << argv[0] << " <json_file>" << std::endl;
+    std::cerr << "Debug tool to visualize arena memory layout from commit "
+                 "request JSON"
+              << std::endl;
+    return 1;
+  }
+
+  const char *filename = argv[1];
+
+  // Read JSON file
+  std::ifstream file(filename);
+  if (!file.is_open()) {
+    std::cerr << "Error: Could not open file '" << filename << "'" << std::endl;
+    return 1;
+  }
+
+  std::ostringstream ss;
+  ss << file.rdbuf();
+  std::string json_content = ss.str();
+  file.close();
+
+  if (json_content.empty()) {
+    std::cerr << "Error: File is empty or could not be read" << std::endl;
+    return 1;
+  }
+
+  std::cout << "Reading commit request from: " << filename << std::endl;
+  std::cout << "JSON size: " << json_content.size() << " bytes" << std::endl;
+  std::cout << std::endl;
+
+  // Parse the commit request
+  CommitRequest commit_request;
+
+  // Make a mutable copy for parsing (weaseljson requires mutable data)
+  std::vector<char> mutable_json(json_content.begin(), json_content.end());
+  mutable_json.push_back('\0'); // Null terminate for safety
+
+  bool parse_success =
+      commit_request.parse_json(mutable_json.data(), mutable_json.size() - 1);
+
+  if (!parse_success || !commit_request.is_parse_complete()) {
+    std::cerr << "Error: Failed to parse JSON" << std::endl;
+    if (commit_request.has_parse_error()) {
+      std::cerr << "Parse error: " << commit_request.get_parse_error()
+                << std::endl;
+    }
+    return 1;
+  }
+
+  std::cout << "Successfully parsed commit request!" << std::endl;
+  std::cout << std::endl;
+
+  // Create debugger and visualize
+  ArenaDebugger debugger(commit_request);
+  debugger.visualize_arena();
+
+  return 0;
+}