Add max_memory_usage field to tidesdb_config_t

src/tidesdb.lua

@@ -93,6 +93,7 @@ ffi.cdef[[
         size_t max_open_sstables;
         int log_to_file;
         size_t log_truncation_at;
+        size_t max_memory_usage;
     } tidesdb_config_t;
 
     typedef struct {
@@ -361,6 +362,7 @@ function tidesdb.default_config()
         max_open_sstables = 256,
         log_to_file = false,
         log_truncation_at = 24 * 1024 * 1024,
+        max_memory_usage = 0,
     }
 end
 
@@ -848,6 +850,7 @@ function TidesDB.new(config)
     c_config.max_open_sstables = config.max_open_sstables or 256
     c_config.log_to_file = config.log_to_file and 1 or 0
     c_config.log_truncation_at = config.log_truncation_at or 24 * 1024 * 1024
+    c_config.max_memory_usage = config.max_memory_usage or 0
 
     local db_ptr = ffi.new("void*[1]")
     local result = lib.tidesdb_open(c_config, db_ptr)
@@ -868,6 +871,7 @@ function TidesDB.open(path, options)
         max_open_sstables = options.max_open_sstables or 256,
         log_to_file = options.log_to_file or false,
         log_truncation_at = options.log_truncation_at or 24 * 1024 * 1024,
+        max_memory_usage = options.max_memory_usage or 0,
     }
     return TidesDB.new(config)
 end

test_max_memory.lua

@@ -0,0 +1,53 @@
+--[[
+Test script to verify max_memory_usage field addition to tidesdb_config_t
+This tests that the new field can be set and the database opens successfully.
+]]
+
+local tidesdb = require("tidesdb")
+
+print("=== Testing max_memory_usage field ===\n")
+
+-- Test 1: Default config includes max_memory_usage
+print("Test 1: Checking default_config()...")
+local default_cfg = tidesdb.default_config()
+assert(default_cfg.max_memory_usage ~= nil, "max_memory_usage should exist in default config")
+print("✓ max_memory_usage found in default config: " .. tostring(default_cfg.max_memory_usage))
+
+-- Test 2: Open database with default max_memory_usage (0 = unlimited)
+print("\nTest 2: Opening database with default max_memory_usage...")
+local path1 = "./test_db_max_mem_default"
+os.execute("rm -rf " .. path1)
+local db1 = tidesdb.TidesDB.open(path1)
+print("✓ Database opened successfully with default max_memory_usage")
+db1:close()
+os.execute("rm -rf " .. path1)
+
+-- Test 3: Open database with custom max_memory_usage
+print("\nTest 3: Opening database with custom max_memory_usage...")
+local path2 = "./test_db_max_mem_custom"
+os.execute("rm -rf " .. path2)
+local db2 = tidesdb.TidesDB.open(path2, {
+    max_memory_usage = 512 * 1024 * 1024  -- 512 MB
+})
+print("✓ Database opened successfully with max_memory_usage = 512 MB")
+db2:close()
+os.execute("rm -rf " .. path2)
+
+-- Test 4: Test with TidesDB.new() constructor
+print("\nTest 4: Testing with TidesDB.new() constructor...")
+local path3 = "./test_db_max_mem_new"
+os.execute("rm -rf " .. path3)
+local config = {
+    db_path = path3,
+    num_flush_threads = 2,
+    num_compaction_threads = 2,
+    max_memory_usage = 256 * 1024 * 1024  -- 256 MB
+}
+local db3 = tidesdb.TidesDB.new(config)
+print("✓ Database created with TidesDB.new() with max_memory_usage = 256 MB")
+db3:close()
+os.execute("rm -rf " .. path3)
+
+print("\n=== All tests passed! ===")
+print("\nThe max_memory_usage field has been successfully added to tidesdb_config_t.")
+print("You can now configure memory limits when opening a TidesDB database.")