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#!/usr/bin/env tarantool local ffi = require('ffi') ffi.cdef[[ int printf(const char *format, ...); ]] ffi.C.printf("Hello, %s\n", os.getenv("USER"));
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See more recipes on `Tarantool GitHub <https://github.com/tarantool/examples/tree/master/cookbook>`__.
hello_world.lua
The standard example of a simple program.
#!/usr/bin/env tarantool

print('Hello, World!')
console_start.lua
Use :doc:`box.once() </reference/reference_lua/box_once>` to initialize a database (creating spaces) if this is the first time the server has been run. Then use :ref:`console.start() <console-start>` to start interactive mode.
#!/usr/bin/env tarantool

-- Configure database
box.cfg {
listen = 3313
}

box.once("bootstrap", function()
box.schema.space.create('tweedledum')
box.space.tweedledum:create_index('primary',
{ type = 'TREE', parts = {1, 'unsigned'}})
end)

require('console').start()
fio_read.lua
Use the :ref:`fio module <fio-module>` to open, read, and close a file.
#!/usr/bin/env tarantool

local fio = require('fio')
local errno = require('errno')
local f = fio.open('/tmp/xxxx.txt', {'O_RDONLY' })
if not f then
error("Failed to open file: "..errno.strerror())
end
local data = f:read(4096)
f:close()
print(data)
fio_write.lua
Use the :ref:`fio module <fio-module>` to open, write, and close a file.
#!/usr/bin/env tarantool

local fio = require('fio')
local errno = require('errno')
local f = fio.open('/tmp/xxxx.txt', {'O_CREAT', 'O_WRONLY', 'O_APPEND'},
tonumber('0666', 8))
if not f then
error("Failed to open file: "..errno.strerror())
end
f:write("Hello\n");
f:close()
ffi_printf.lua
Use the `LuaJIT ffi library <http://luajit.org/ext_ffi.html>`_ to call a C built-in function: printf(). (For help understanding ffi, see the `FFI tutorial <http://luajit.org/ext_ffi_tutorial.html>`_.)
#!/usr/bin/env tarantool

local ffi = require('ffi')
ffi.cdef[[
int printf(const char *format, ...);
]]

ffi.C.printf("Hello, %s\n", os.getenv("USER"));
ffi_gettimeofday.lua
Use the `LuaJIT ffi library <http://luajit.org/ext_ffi.html>`_ to call a C function: gettimeofday(). This delivers time with millisecond precision, unlike the time function in Tarantool's :ref:`clock module <clock-module>`.
#!/usr/bin/env tarantool

local ffi = require('ffi')
ffi.cdef[[
typedef long time_t;
typedef struct timeval {
time_t tv_sec;
time_t tv_usec;
} timeval;
int gettimeofday(struct timeval *t, void *tzp);
]]

local timeval_buf = ffi.new("timeval")
local now = function()
ffi.C.gettimeofday(timeval_buf, nil)
return tonumber(timeval_buf.tv_sec * 1000 + (timeval_buf.tv_usec / 1000))
end
ffi_zlib.lua
Use the `LuaJIT ffi library <http://luajit.org/ext_ffi.html>`_ to call a C library function. (For help understanding ffi, see the `FFI tutorial <http://luajit.org/ext_ffi_tutorial.html>`_.)
#!/usr/bin/env tarantool

local ffi = require("ffi")
ffi.cdef[[
unsigned long compressBound(unsigned long sourceLen);
int compress2(uint8_t *dest, unsigned long *destLen,
const uint8_t *source, unsigned long sourceLen, int level);
int uncompress(uint8_t *dest, unsigned long *destLen,
const uint8_t *source, unsigned long sourceLen);
]]
local zlib = ffi.load(ffi.os == "Windows" and "zlib1" or "z")

-- Lua wrapper for compress2()
local function compress(txt)
local n = zlib.compressBound(#txt)
local buf = ffi.new("uint8_t[?]", n)
local buflen = ffi.new("unsigned long[1]", n)
local res = zlib.compress2(buf, buflen, txt, #txt, 9)
assert(res == 0)
return ffi.string(buf, buflen[0])
end

-- Lua wrapper for uncompress
local function uncompress(comp, n)
local buf = ffi.new("uint8_t[?]", n)
local buflen = ffi.new("unsigned long[1]", n)
local res = zlib.uncompress(buf, buflen, comp, #comp)
assert(res == 0)
return ffi.string(buf, buflen[0])
end

-- Simple test code.
local txt = string.rep("abcd", 1000)
print("Uncompressed size: ", #txt)
local c = compress(txt)
print("Compressed size: ", #c)
local txt2 = uncompress(c, #txt)
assert(txt2 == txt)
ffi_meta.lua
Use the `LuaJIT ffi library <http://luajit.org/ext_ffi.html>`_ to access a C object via a metamethod (a method which is defined with a metatable).
#!/usr/bin/env tarantool

local ffi = require("ffi")
ffi.cdef[[
typedef struct { double x, y; } point_t;
]]

local point
local mt = {
__add = function(a, b) return point(a.x+b.x, a.y+b.y) end,
__len = function(a) return math.sqrt(a.x*a.x + a.y*a.y) end,
__index = {
area = function(a) return a.x*a.x + a.y*a.y end,
},
}
point = ffi.metatype("point_t", mt)

local a = point(3, 4)
print(a.x, a.y) --> 3 4
print(#a) --> 5
print(a:area()) --> 25
local b = a + point(0.5, 8)
print(#b) --> 12.5
ffi_varbinary_insert.lua
Use the `LuaJIT ffi library <http://luajit.org/ext_ffi.html>`_ to insert a tuple which has a VARBINARY field.
Note that it is allowed only inside a memtx transaction: when ``box_insert()`` does not yield.
Lua does not have direct support for VARBINARY, so using C is one way to put in data which in MessagePack is stored as bin (MP_BIN). If the tuple is retrieved later, field "b" will have type = 'cdata'.
#!/usr/bin/env tarantool

-- box.cfg{} should be here

s = box.schema.space.create('withdata')
s:format({{"b", "varbinary"}})
s:create_index('pk', {parts = {1, "varbinary"}})

buffer = require('buffer')
ffi = require('ffi')

function varbinary_insert(space, bytes)
local tmpbuf = buffer.ibuf()
local p = tmpbuf:alloc(3 + #bytes)
p[0] = 0x91 -- MsgPack code for "array-1"
p[1] = 0xC4 -- MsgPack code for "bin-8" so up to 256 bytes
p[2] = #bytes
for i, c in pairs(bytes) do p[i + 3 - 1] = c end
ffi.cdef[[int box_insert(uint32_t space_id,
const char *tuple,
const char *tuple_end,
box_tuple_t **result);]]
ffi.C.box_insert(space.id, tmpbuf.rpos, tmpbuf.wpos, nil)
tmpbuf:recycle()
end

varbinary_insert(s, {0xDE, 0xAD, 0xBE, 0xAF})
varbinary_insert(s, {0xFE, 0xED, 0xFA, 0xCE})

-- if successful, Tarantool enters the event loop now
print_arrays.lua

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testing_project / Documentation: how-to/app/cookbook — English

#!/usr/bin/env tarantool

local ffi = require('ffi')
ffi.cdef[[
int printf(const char *format, ...);
]]

ffi.C.printf("Hello, %s\n", os.getenv("USER"));
a year ago
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python-format, read-only
String age
a year ago
Last updated
a year ago
Source string age
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