### Build Example with GLib2

Source: https://github.com/snapchat/keydb/blob/main/deps/hiredis/examples/CMakeLists.txt

Configures and builds an example executable that links against Hiredis and GLib2. Requires GLib2 development files to be installed.

```cmake
INCLUDE(FindPkgConfig)
# Check for GLib

PKG_CHECK_MODULES(GLIB2 glib-2.0)
if (GLIB2_FOUND)
    INCLUDE_DIRECTORIES(${GLIB2_INCLUDE_DIRS})
    LINK_DIRECTORIES(${GLIB2_LIBRARY_DIRS})
    ADD_EXECUTABLE(example-glib example-glib.c)
    TARGET_LINK_LIBRARIES(example-glib hiredis ${GLIB2_LIBRARIES})
ENDIF(GLIB2_FOUND)
```

--------------------------------

### Configure Installation Prefix

Source: https://github.com/snapchat/keydb/blob/main/deps/jemalloc/INSTALL.md

Set the base directory for jemalloc installation. This example installs files into /usr/local.

```bash
./configure --prefix=/usr/local
```

--------------------------------

### Build Basic Hiredis Example

Source: https://github.com/snapchat/keydb/blob/main/deps/hiredis/examples/CMakeLists.txt

Configures and builds a basic example executable that links only against Hiredis.

```cmake
ADD_EXECUTABLE(example example.c)
TARGET_LINK_LIBRARIES(example hiredis)
```

--------------------------------

### Build Example with libuv

Source: https://github.com/snapchat/keydb/blob/main/deps/hiredis/examples/CMakeLists.txt

Configures and builds an example executable that links against Hiredis and libuv. Requires libuv development files.

```cmake
FIND_PATH(LIBUV uv.h)
IF (LIBUV)
    ADD_EXECUTABLE(example-libuv example-libuv.c)
    TARGET_LINK_LIBRARIES(example-libuv hiredis uv)
ENDIF()
```

--------------------------------

### Build Example with libev

Source: https://github.com/snapchat/keydb/blob/main/deps/hiredis/examples/CMakeLists.txt

Configures and builds an example executable that links against Hiredis and libev. Requires libev development files.

```cmake
FIND_PATH(LIBEV ev.h
    HINTS /usr/local /usr/opt/local
    ENV LIBEV_INCLUDE_DIR)

if (LIBEV)
    # Just compile and link with libev
    ADD_EXECUTABLE(example-libev example-libev.c)
    TARGET_LINK_LIBRARIES(example-libev hiredis ev)
ENDIF()
```

--------------------------------

### Installation and Package Configuration

Source: https://github.com/snapchat/keydb/blob/main/deps/cpp-statsd-client/CMakeLists.txt

Configures installation rules for the library targets, package version file, and CMake configuration files. It ensures the library, headers, and configuration are installed to the correct locations.

```cmake
# The installation and pkg-config-like cmake config
install(TARGETS ${PROJECT_NAME}
        EXPORT ${PROJECT_NAME}_Targets
        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
write_basic_package_version_file("${PROJECT_NAME}ConfigVersion.cmake"
                                 VERSION ${PROJECT_VERSION}
                                 COMPATIBILITY SameMajorVersion)
configure_package_config_file(
  "${PROJECT_SOURCE_DIR}/cmake/${PROJECT_NAME}Config.cmake.in"
  "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
  INSTALL_DESTINATION
  ${CMAKE_INSTALL_DATAROOTDIR}/${PROJECT_NAME}/cmake)
install(EXPORT ${PROJECT_NAME}_Targets
        FILE ${PROJECT_NAME}Targets.cmake
        NAMESPACE ${PROJECT_NAME}::
        DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/${PROJECT_NAME}/cmake)
install(FILES "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
              "${PROJECT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake"
        DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/${PROJECT_NAME}/cmake)
install(DIRECTORY ${PROJECT_SOURCE_DIR}/include DESTINATION include)
```

--------------------------------

### Build and Install Memkind

Source: https://github.com/snapchat/keydb/blob/main/deps/memkind/src/README.md

Builds and installs the memkind library using the provided build script.

```bash
./build.sh
make install
```

--------------------------------

### Build Hiredis Push Example

Source: https://github.com/snapchat/keydb/blob/main/deps/hiredis/examples/CMakeLists.txt

Configures and builds an example executable for Hiredis push functionality, linking against Hiredis.

```cmake
ADD_EXECUTABLE(example-push example-push.c)
TARGET_LINK_LIBRARIES(example-push hiredis)
```

--------------------------------

### Build Example for macOS with CoreFoundation

Source: https://github.com/snapchat/keydb/blob/main/deps/hiredis/examples/CMakeLists.txt

Configures and builds an example executable for macOS that links against Hiredis and the CoreFoundation framework.

```cmake
IF (APPLE)
    FIND_LIBRARY(CF CoreFoundation)
    ADD_EXECUTABLE(example-macosx example-macosx.c)
    TARGET_LINK_LIBRARIES(example-macosx hiredis ${CF})
ENDIF()
```

--------------------------------

### Build Example with libevent

Source: https://github.com/snapchat/keydb/blob/main/deps/hiredis/examples/CMakeLists.txt

Configures and builds an example executable that links against Hiredis and libevent. Requires libevent development files.

```cmake
FIND_PATH(LIBEVENT event.h)
if (LIBEVENT)
    ADD_EXECUTABLE(example-libevent example-libevent)
    TARGET_LINK_LIBRARIES(example-libevent hiredis event)
ENDIF()
```

--------------------------------

### Install Additional Build Dependencies

Source: https://github.com/snapchat/keydb/blob/main/README.md

Install optional dependencies that may be needed for certain KeyDB build configurations.

```bash
% sudo apt-get install autoconf autotools-dev libnuma-dev libtool
```

--------------------------------

### Build and Install Developer Sources

Source: https://github.com/snapchat/keydb/blob/main/deps/jemalloc/INSTALL.md

Steps for building and installing from unpackaged developer sources. This sequence may be necessary when working with the latest development code.

```bash
./autogen.sh
make dist
make
make install
```

--------------------------------

### Install KeyDB Binaries

Source: https://github.com/snapchat/keydb/blob/main/README.md

Install KeyDB binaries to the default /usr/local/bin directory. You can specify a different destination using the PREFIX variable.

```bash
% make install
```

```bash
make PREFIX=/some/other/directory install
```

--------------------------------

### Configure with Installation Suffix

Source: https://github.com/snapchat/keydb/blob/main/deps/memkind/src/jemalloc/INSTALL.md

Append a suffix to installed file names using --with-install-suffix to allow multiple versions.

```bash
--with-install-suffix=<suffix>
```

--------------------------------

### Install Hiredis SSL Library and Headers

Source: https://github.com/snapchat/keydb/blob/main/deps/hiredis/CMakeLists.txt

Installs the hiredis_ssl library, headers, and pkg-config file. This is done only if ENABLE_SSL is set to ON.

```cmake
INSTALL(TARGETS hiredis_ssl
        EXPORT hiredis_ssl-targets
        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})

    INSTALL(FILES hiredis_ssl.h
        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/hiredis)
    
    INSTALL(FILES ${CMAKE_CURRENT_BINARY_DIR}/hiredis_ssl.pc
        DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
```

--------------------------------

### Install C++ StatsD Client using Makefile

Source: https://github.com/snapchat/keydb/blob/main/deps/cpp-statsd-client/README.md

Use this command to install the header files for the C++ StatsD client.

```shell
make install
```

--------------------------------

### Build and Install Packaged Release

Source: https://github.com/snapchat/keydb/blob/main/deps/jemalloc/INSTALL.md

Standard procedure for installing a packaged release of jemalloc. Ensure you are in the root directory of the source tree.

```bash
./configure
make
make install
```

--------------------------------

### Jemalloc Installation with Make Variables

Source: https://github.com/snapchat/keydb/blob/main/deps/jemalloc/INSTALL.md

Optionally define make variables when invoking make for custom installation paths and build configurations.

```makefile
INCLUDEDIR="?"
LIBDIR="?"
MANDIR="?"
DESTDIR="?"
CC="?"
CFLAGS="?"
CPPFLAGS="?"
LDFLAGS="?"
PATH="?"
```

--------------------------------

### Lua Table Constructor Equivalent

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Shows the equivalent imperative code for the complex table constructor example. This clarifies how fields are assigned and indexed.

```lua
do
  local t = {}
  t[f(1)] = g
  t[1] = "x"         -- 1st exp
  t[2] = "y"         -- 2nd exp
  t.x = 1            -- t["x"] = 1
  t[3] = f(x)        -- 3rd exp
  t[30] = 23
  t[4] = 45          -- 4th exp
  a = t
end
```

--------------------------------

### Lua Logical Operators Examples

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Demonstrates the short-circuiting behavior and return values of Lua's 'and' and 'or' logical operators.

```lua
10 or 20
--> 10
10 or error()
--> 10
nil or "a"
--> "a"
nil and 10
--> nil
false and error()
--> false
false and nil
--> false
false or nil
--> nil
10 and 20
--> 20
```

--------------------------------

### Lua Coroutine Example

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Demonstrates the creation and sequential resumption of a Lua coroutine, showing the flow of control and data between the main thread and the coroutine body.

```lua
function foo (a)
  print("foo", a)
  return coroutine.yield(2*a)
end

co = coroutine.create(function (a,b)
      print("co-body", a, b)
      local r = foo(a+1)
      print("co-body", r)
      local r, s = coroutine.yield(a+b, a-b)
      print("co-body", r, s)
      return b, "end"
end)
        
print("main", coroutine.resume(co, 1, 10))
print("main", coroutine.resume(co, "r"))
print("main", coroutine.resume(co, "x", "y"))
print("main", coroutine.resume(co, "x", "y"))
```

--------------------------------

### Lua Closures and Upvalues Example

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Shows how closures created within a loop capture distinct local variables (upvalues) and share outer local variables.

```lua
a = {}
local x = 20
for i=1,10 do
  local y = 0
  a[i] = function () y=y+1; return x+y end
end
```

--------------------------------

### Lua Multiple Assignment Example

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Demonstrates multiple variable assignment and value adjustment. Excess values are discarded, and fewer values are padded with nil.

```lua
i = 3
i, a[i] = i+1, 20
```

```lua
x, y = y, x
```

```lua
x, y, z = y, z, x
```

--------------------------------

### Example C Function for Lua

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

An example C function that calculates the average and sum of numerical arguments passed from Lua. It demonstrates stack manipulation, type checking, and returning multiple values.

```c
static int foo (lua_State *L) {
  int n = lua_gettop(L);    /* number of arguments */
  lua_Number sum = 0;
  int i;
  for (i = 1; i <= n; i++) {
    if (!lua_isnumber(L, i)) {
      lua_pushstring(L, "incorrect argument");
      lua_error(L);
    }
    sum += lua_tonumber(L, i);
  }
  lua_pushnumber(L, sum/n);        /* first result */
  lua_pushnumber(L, sum);         /* second result */
  return 2;                   /* number of results */
}
```

--------------------------------

### Lua Lexical Scoping Example

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Demonstrates lexical scoping in Lua, showing how local variables are declared within blocks and how inner scopes can access outer variables.

```lua
x = 10                -- global variable
do                    -- new block
  local x = x         -- new 'x', with value 10
  print(x)          --> 10
  x = x+1
  do                  -- another block
    local x = x+1     -- another 'x'
    print(x)          --> 12
  end
  print(x)            --> 11
end
print(x)              --> 10  (the global one)
```

--------------------------------

### Lua Table Constructor Initialization

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Demonstrates initializing a Lua table with various field types, including computed keys, string keys, sequential elements, and explicit numerical keys. Fields are added sequentially starting from 1 unless explicitly keyed.

```lua
a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 }
```

--------------------------------

### Lua Non-Tail Call Example

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

These examples are not tail calls because they involve adjustments to return values, additional expressions, or discarding results, preventing stack frame reuse.

```lua
return 2 * f(x)
```

```lua
return x, f(x)
```

```lua
f(x); return
```

```lua
return x or f(x)
```

--------------------------------

### Creating a Coroutine

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Use `coroutine.create` to create a new coroutine. It takes a function as an argument, which serves as the coroutine's main function. This function only creates the coroutine and returns a handle; it does not start execution.

```Lua
coroutine.create(function() ... end)
```

--------------------------------

### Lua Arithmetic Operators

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Provides examples of Lua's standard arithmetic operators, including binary operators (+, -, *, /, %, ^) and the unary negation operator (-). Operations are performed on numbers or strings convertible to numbers.

```lua
x^(-0.5) computes the inverse of the square root of x
```

--------------------------------

### Lua Tail Call Example

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

This is NOT a tail call. Lua requires a specific syntax for tail calls where the 'return' statement directly precedes a single function call to reuse the stack frame.

```lua
return (f(x))
```

--------------------------------

### Accessing Global Variables in Lua C API

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Demonstrates how to get the value of a global variable from Lua's environment table using lua_getfield.

```c
lua_getfield(L, LUA_GLOBALSINDEX, varname);
```

--------------------------------

### Resuming a Coroutine

Source: https://github.com/snapchat/keydb/blob/main/deps/lua/doc/manual.html

Call `coroutine.resume` to start or resume a coroutine. Pass the coroutine's handle as the first argument. Any additional arguments are passed to the coroutine's main function or the point where it yielded. Returns `true` on success, `false` on error.

```Lua
coroutine.resume(thread, arg1, arg2)
```

--------------------------------

### Basic Project Setup

Source: https://github.com/snapchat/keydb/blob/main/deps/cpp-statsd-client/CMakeLists.txt

Initializes the CMake build system, sets the project name, version, language, description, and homepage URL.

```cmake
cmake_minimum_required(VERSION 3.5)
project(cpp-statsd-client
        VERSION 1.0.2
        LANGUAGES CXX
        DESCRIPTION "A header-only StatsD client implemented in C++"
        HOMEPAGE_URL "https://github.com/vthiery/cpp-statsd-client")
```

--------------------------------

### Enable Active-Active Replication

Source: https://github.com/snapchat/keydb/blob/main/README.md

Enable active-active replication, allowing multiple instances to accept reads and writes while staying synced. Refer to KeyDB documentation for detailed setup and examples.

```config
active-replica yes
```