[tarantool-patches] Re: [PATCH 1/1] buffer: port static allocator to Lua
Vladislav Shpilevoy
v.shpilevoy at tarantool.org
Sat May 18 21:41:04 MSK 2019
Still waiting a review.
On 15/05/2019 16:33, Vladislav Shpilevoy wrote:
> Static allocator gives memory blocks from cyclic BSS memory
> block of 3 pages 4096 bytes each. It is much faster than
> malloc, when a temporary buffer is needed.
>
> This commit exposes the allocator to Lua, which suffers from
> lack of ability to pass values by pointers into FFI functions,
> nor has a stack to allocate small buffers like 'char[256]'.
> Also these allocations complicate and slow down GC job.
>
> Static allocator solves most of these problems provindg a way to
> swiftly allocate temporary memory blocks. Besides, for the most
> annoying problem with ffi.new(<type>[1]) the buffer module now
> exposes a statically allocated array of scalar values able to fit
> any 'int', 'char', 'size_t' ... and ready at hand.
>
> A simple micro benchmark showed, that ffi.new() vs
> buffer.static_alloc() is ~100 times slower, even on small
> allocations of 1Kb, and ~1.5 times slower on tiny allocations
> of 10 bytes. The results do not account GC. It is remarkable,
> buffer.static_alloc() speed does not depend on size, while
> ffi.new() strongly depends.
>
> The commit is motivated by one another place where
> ffi.new('int[1]') appeared, in SWIM module, to obtain payload
> size as an out parameter of a C function.
> ---
> Branch: https://github.com/tarantool/tarantool/tree/gerold103/static-allocator-lua
>
> extra/exports | 2 ++
> src/CMakeLists.txt | 1 +
> src/box/lua/schema.lua | 3 +-
> src/lua/buffer.c | 42 +++++++++++++++++++++++++++
> src/lua/buffer.lua | 61 ++++++++++++++++++++++++++++++++++++++++
> src/lua/crypto.lua | 22 +++++++--------
> src/lua/digest.lua | 7 +++--
> src/lua/fio.lua | 3 +-
> src/lua/init.c | 2 +-
> src/lua/msgpackffi.lua | 50 +++++++++++++-------------------
> src/lua/socket.lua | 36 ++++++++++++++----------
> src/lua/string.lua | 10 ++++---
> src/lua/uri.lua | 7 +++--
> src/lua/uuid.lua | 9 +++---
> test/app/buffer.result | 53 ++++++++++++++++++++++++++++++++++
> test/app/buffer.test.lua | 23 +++++++++++++++
> 16 files changed, 256 insertions(+), 75 deletions(-)
> create mode 100644 src/lua/buffer.c
> create mode 100644 test/app/buffer.result
> create mode 100644 test/app/buffer.test.lua
>
> diff --git a/extra/exports b/extra/exports
> index 4f41a17b3..5375a01e4 100644
> --- a/extra/exports
> +++ b/extra/exports
> @@ -85,6 +85,8 @@ tnt_EVP_MD_CTX_free
> tnt_HMAC_CTX_new
> tnt_HMAC_CTX_free
>
> +lua_static_aligned_alloc
> +
> # Module API
>
> _say
> diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
> index a6a18142b..492b8712e 100644
> --- a/src/CMakeLists.txt
> +++ b/src/CMakeLists.txt
> @@ -116,6 +116,7 @@ set (server_sources
> lua/utf8.c
> lua/info.c
> lua/string.c
> + lua/buffer.c
> ${lua_sources}
> ${PROJECT_SOURCE_DIR}/third_party/lua-yaml/lyaml.cc
> ${PROJECT_SOURCE_DIR}/third_party/lua-yaml/b64.c
> diff --git a/src/box/lua/schema.lua b/src/box/lua/schema.lua
> index f31cf7f2c..fa6c7c9a4 100644
> --- a/src/box/lua/schema.lua
> +++ b/src/box/lua/schema.lua
> @@ -7,6 +7,7 @@ local fun = require('fun')
> local log = require('log')
> local fio = require('fio')
> local json = require('json')
> +local static_alloc = require('buffer').static_alloc
> local session = box.session
> local internal = require('box.internal')
> local function setmap(table)
> @@ -2103,7 +2104,7 @@ box.schema.user = {}
>
> box.schema.user.password = function(password)
> local BUF_SIZE = 128
> - local buf = ffi.new("char[?]", BUF_SIZE)
> + local buf = static_alloc('char', BUF_SIZE)
> builtin.password_prepare(password, #password, buf, BUF_SIZE)
> return ffi.string(buf)
> end
> diff --git a/src/lua/buffer.c b/src/lua/buffer.c
> new file mode 100644
> index 000000000..5fd349261
> --- /dev/null
> +++ b/src/lua/buffer.c
> @@ -0,0 +1,42 @@
> +/*
> + * Copyright 2010-2019, Tarantool AUTHORS, please see AUTHORS file.
> + *
> + * Redistribution and use in source and binary forms, with or
> + * without modification, are permitted provided that the following
> + * conditions are met:
> + *
> + * 1. Redistributions of source code must retain the above
> + * copyright notice, this list of conditions and the
> + * following disclaimer.
> + *
> + * 2. Redistributions in binary form must reproduce the above
> + * copyright notice, this list of conditions and the following
> + * disclaimer in the documentation and/or other materials
> + * provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
> + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
> + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
> + * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
> + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
> + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
> + * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + */
> +#include "small/static.h"
> +
> +/**
> + * Static inline functions like in static.h can't be exported.
> + * Here they are given a symbol to export.
> + */
> +
> +void *
> +lua_static_aligned_alloc(size_t size, size_t alignment)
> +{
> + return static_aligned_alloc(size, alignment);
> +}
> diff --git a/src/lua/buffer.lua b/src/lua/buffer.lua
> index a72d8d1f9..7fd9f46ed 100644
> --- a/src/lua/buffer.lua
> +++ b/src/lua/buffer.lua
> @@ -33,6 +33,37 @@ ibuf_reinit(struct ibuf *ibuf);
>
> void *
> ibuf_reserve_slow(struct ibuf *ibuf, size_t size);
> +
> +void *
> +lua_static_aligned_alloc(size_t size, size_t alignment);
> +
> +/**
> + * Scalar is a buffer to use with FFI functions, which usually
> + * operate with pointers to scalar values like int, char, size_t,
> + * void *. To avoid doing 'ffi.new(<type>[1])' on each such FFI
> + * function invocation, a module can use one of attributes of the
> + * scalar union.
> + *
> + * Naming policy of the attributes is easy to remember:
> + * 'a' for array type + type name first letters + 'p' for pointer.
> + *
> + * For example:
> + * - int[1] - <a>rray of <i>nt - ai;
> + * - const unsigned char *[1] -
> + * <a>rray of <c>onst <u>nsigned <c>har <p> pointer - acucp.
> + */
> +union scalar {
> + size_t as[1];
> + void *ap[1];
> + int ai[1];
> + char ac[1];
> + const unsigned char *acucp[1];
> + unsigned long aul[1];
> + uint16_t u16;
> + uint32_t u32;
> + uint64_t u64;
> + int64_t i64;
> +};
> ]]
>
> local builtin = ffi.C
> @@ -174,8 +205,38 @@ local function ibuf_new(arg, arg2)
> errorf('Usage: ibuf([size])')
> end
>
> +--
> +-- Allocate a chunk of static BSS memory, or use ordinal ffi.new,
> +-- when too big size.
> +-- @param type C type - a struct, a basic type, etc. Should be a
> +-- string: 'int', 'char *', 'struct tuple', etc.
> +-- @param size Optional argument, number of elements of @a type to
> +-- allocate. 1 by default.
> +-- @return Cdata pointer to @a type.
> +--
> +local function static_alloc(type, size)
> + size = size or 1
> + local bsize = size * ffi.sizeof(type)
> + local ptr = builtin.lua_static_aligned_alloc(bsize, ffi.alignof(type))
> + if ptr ~= nil then
> + return ffi.cast(type..' *', ptr)
> + end
> + return ffi.new(type..'[?]', size)
> +end
> +
> +--
> +-- Sometimes it is wanted to use several temporary scalar cdata
> +-- values. Then one union object is not enough - its attributes
> +-- share memory.
> +--
> +local scalar_array = ffi.new('union scalar[?]', 2)
> +
> return {
> ibuf = ibuf_new;
> IBUF_SHARED = ffi.C.tarantool_lua_ibuf;
> READAHEAD = READAHEAD;
> + static_alloc = static_alloc,
> + scalar_array = scalar_array,
> + -- Fast access when only one variable is needed.
> + scalar = scalar_array[0],
> }
> diff --git a/src/lua/crypto.lua b/src/lua/crypto.lua
> index e76370517..7db6afac9 100644
> --- a/src/lua/crypto.lua
> +++ b/src/lua/crypto.lua
> @@ -2,6 +2,7 @@
>
> local ffi = require('ffi')
> local buffer = require('buffer')
> +local scalar = buffer.scalar
>
> ffi.cdef[[
> int tnt_openssl_init(void);
> @@ -84,7 +85,6 @@ local function digest_new(digest)
> digest = digest,
> buf = buffer.ibuf(64),
> initialized = false,
> - outl = ffi.new('int[1]')
> }, digest_mt)
> self:init()
> return self
> @@ -114,10 +114,10 @@ local function digest_final(self)
> return error('Digest not initialized')
> end
> self.initialized = false
> - if ffi.C.EVP_DigestFinal_ex(self.ctx, self.buf.wpos, self.outl) ~= 1 then
> + if ffi.C.EVP_DigestFinal_ex(self.ctx, self.buf.wpos, scalar.ai) ~= 1 then
> return error('Can\'t finalize digest: ' .. openssl_err_str())
> end
> - return ffi.string(self.buf.wpos, self.outl[0])
> + return ffi.string(self.buf.wpos, scalar.ai[0])
> end
>
> local function digest_free(self)
> @@ -156,9 +156,7 @@ local function hmac_new(digest, key)
> local self = setmetatable({
> ctx = ctx,
> digest = digest,
> - buf = buffer.ibuf(64),
> initialized = false,
> - outl = ffi.new('int[1]')
> }, hmac_mt)
> self:init(key)
> return self
> @@ -188,10 +186,11 @@ local function hmac_final(self)
> return error('HMAC not initialized')
> end
> self.initialized = false
> - if ffi.C.HMAC_Final(self.ctx, self.buf.wpos, self.outl) ~= 1 then
> + local buf = buffer.static_alloc('char', 64)
> + if ffi.C.HMAC_Final(self.ctx, buf, scalar.ai) ~= 1 then
> return error('Can\'t finalize HMAC: ' .. openssl_err_str())
> end
> - return ffi.string(self.buf.wpos, self.outl[0])
> + return ffi.string(buf, scalar.ai[0])
> end
>
> local function hmac_free(self)
> @@ -254,7 +253,6 @@ local function cipher_new(cipher, key, iv, direction)
> direction = direction,
> buf = buffer.ibuf(),
> initialized = false,
> - outl = ffi.new('int[1]')
> }, cipher_mt)
> self:init(key, iv)
> return self
> @@ -279,10 +277,10 @@ local function cipher_update(self, input)
> error("Usage: cipher:update(string)")
> end
> local wpos = self.buf:reserve(input:len() + self.block_size - 1)
> - if ffi.C.EVP_CipherUpdate(self.ctx, wpos, self.outl, input, input:len()) ~= 1 then
> + if ffi.C.EVP_CipherUpdate(self.ctx, wpos, scalar.ai, input, input:len()) ~= 1 then
> return error('Can\'t update cipher:' .. openssl_err_str())
> end
> - return ffi.string(wpos, self.outl[0])
> + return ffi.string(wpos, scalar.ai[0])
> end
>
> local function cipher_final(self)
> @@ -291,11 +289,11 @@ local function cipher_final(self)
> end
> self.initialized = false
> local wpos = self.buf:reserve(self.block_size - 1)
> - if ffi.C.EVP_CipherFinal_ex(self.ctx, wpos, self.outl) ~= 1 then
> + if ffi.C.EVP_CipherFinal_ex(self.ctx, wpos, scalar.ai) ~= 1 then
> return error('Can\'t finalize cipher:' .. openssl_err_str())
> end
> self.initialized = false
> - return ffi.string(wpos, self.outl[0])
> + return ffi.string(wpos, scalar.ai[0])
> end
>
> local function cipher_free(self)
> diff --git a/src/lua/digest.lua b/src/lua/digest.lua
> index 8f199c0af..6ed91cfa2 100644
> --- a/src/lua/digest.lua
> +++ b/src/lua/digest.lua
> @@ -3,6 +3,7 @@
> local ffi = require('ffi')
> local crypto = require('crypto')
> local bit = require('bit')
> +local static_alloc = require('buffer').static_alloc
>
> ffi.cdef[[
> /* internal implementation */
> @@ -179,7 +180,7 @@ local m = {
> end
> local blen = #bin
> local slen = ffi.C.base64_bufsize(blen, mask)
> - local str = ffi.new('char[?]', slen)
> + local str = static_alloc('char', slen)
> local len = ffi.C.base64_encode(bin, blen, str, slen, mask)
> return ffi.string(str, len)
> end,
> @@ -190,7 +191,7 @@ local m = {
> end
> local slen = #str
> local blen = math.ceil(slen * 3 / 4)
> - local bin = ffi.new('char[?]', blen)
> + local bin = static_alloc('char', blen)
> local len = ffi.C.base64_decode(str, slen, bin, blen)
> return ffi.string(bin, len)
> end,
> @@ -228,7 +229,7 @@ local m = {
> if n == nil then
> error('Usage: digest.urandom(len)')
> end
> - local buf = ffi.new('char[?]', n)
> + local buf = static_alloc('char', n)
> ffi.C.random_bytes(buf, n)
> return ffi.string(buf, n)
> end,
> diff --git a/src/lua/fio.lua b/src/lua/fio.lua
> index 38664a556..fce79c277 100644
> --- a/src/lua/fio.lua
> +++ b/src/lua/fio.lua
> @@ -275,8 +275,7 @@ fio.dirname = function(path)
> if type(path) ~= 'string' then
> error("Usage: fio.dirname(path)")
> end
> - path = ffi.new('char[?]', #path + 1, path)
> - return ffi.string(ffi.C.dirname(path))
> + return ffi.string(ffi.C.dirname(ffi.cast('char *', path)))
> end
>
> fio.umask = function(umask)
> diff --git a/src/lua/init.c b/src/lua/init.c
> index be164bdfb..303369841 100644
> --- a/src/lua/init.c
> +++ b/src/lua/init.c
> @@ -126,9 +126,9 @@ static const char *lua_modules[] = {
> "errno", errno_lua,
> "fiber", fiber_lua,
> "env", env_lua,
> + "buffer", buffer_lua,
> "string", string_lua,
> "table", table_lua,
> - "buffer", buffer_lua,
> "msgpackffi", msgpackffi_lua,
> "crypto", crypto_lua,
> "digest", digest_lua,
> diff --git a/src/lua/msgpackffi.lua b/src/lua/msgpackffi.lua
> index 609334cff..1e4786707 100644
> --- a/src/lua/msgpackffi.lua
> +++ b/src/lua/msgpackffi.lua
> @@ -21,19 +21,10 @@ float
> mp_decode_float(const char **data);
> double
> mp_decode_double(const char **data);
> -union tmpint {
> - uint16_t u16;
> - uint32_t u32;
> - uint64_t u64;
> -};
> ]])
>
> local strict_alignment = (jit.arch == 'arm')
> -
> -local tmpint
> -if strict_alignment then
> - tmpint = ffi.new('union tmpint[1]')
> -end
> +local scalar = buffer.scalar
>
> local function bswap_u16(num)
> return bit.rshift(bit.bswap(tonumber(num)), 16)
> @@ -70,10 +61,10 @@ end
> local encode_u16
> if strict_alignment then
> encode_u16 = function(buf, code, num)
> - tmpint[0].u16 = bswap_u16(num)
> + scalar.u16 = bswap_u16(num)
> local p = buf:alloc(3)
> p[0] = code
> - ffi.copy(p + 1, tmpint, 2)
> + ffi.copy(p + 1, scalar, 2)
> end
> else
> encode_u16 = function(buf, code, num)
> @@ -86,11 +77,10 @@ end
> local encode_u32
> if strict_alignment then
> encode_u32 = function(buf, code, num)
> - tmpint[0].u32 =
> - ffi.cast('uint32_t', bit.bswap(tonumber(num)))
> + scalar.u32 = ffi.cast('uint32_t', bit.bswap(tonumber(num)))
> local p = buf:alloc(5)
> p[0] = code
> - ffi.copy(p + 1, tmpint, 4)
> + ffi.copy(p + 1, scalar, 4)
> end
> else
> encode_u32 = function(buf, code, num)
> @@ -104,10 +94,10 @@ end
> local encode_u64
> if strict_alignment then
> encode_u64 = function(buf, code, num)
> - tmpint[0].u64 = bit.bswap(ffi.cast('uint64_t', num))
> + scalar.u64 = bit.bswap(ffi.cast('uint64_t', num))
> local p = buf:alloc(9)
> p[0] = code
> - ffi.copy(p + 1, tmpint, 8)
> + ffi.copy(p + 1, scalar, 8)
> end
> else
> encode_u64 = function(buf, code, num)
> @@ -324,9 +314,9 @@ end
> local decode_u16
> if strict_alignment then
> decode_u16 = function(data)
> - ffi.copy(tmpint, data[0], 2)
> + ffi.copy(scalar, data[0], 2)
> data[0] = data[0] + 2
> - return tonumber(bswap_u16(tmpint[0].u16))
> + return tonumber(bswap_u16(scalar.u16))
> end
> else
> decode_u16 = function(data)
> @@ -339,10 +329,10 @@ end
> local decode_u32
> if strict_alignment then
> decode_u32 = function(data)
> - ffi.copy(tmpint, data[0], 4)
> + ffi.copy(scalar, data[0], 4)
> data[0] = data[0] + 4
> return tonumber(
> - ffi.cast('uint32_t', bit.bswap(tonumber(tmpint[0].u32))))
> + ffi.cast('uint32_t', bit.bswap(tonumber(scalar.u32))))
> end
> else
> decode_u32 = function(data)
> @@ -356,9 +346,9 @@ end
> local decode_u64
> if strict_alignment then
> decode_u64 = function(data)
> - ffi.copy(tmpint, data[0], 8);
> + ffi.copy(scalar, data[0], 8);
> data[0] = data[0] + 8
> - local num = bit.bswap(tmpint[0].u64)
> + local num = bit.bswap(scalar.u64)
> if num <= DBL_INT_MAX then
> return tonumber(num) -- return as 'number'
> end
> @@ -385,8 +375,8 @@ end
> local decode_i16
> if strict_alignment then
> decode_i16 = function(data)
> - ffi.copy(tmpint, data[0], 2)
> - local num = bswap_u16(tmpint[0].u16)
> + ffi.copy(scalar, data[0], 2)
> + local num = bswap_u16(scalar.u16)
> data[0] = data[0] + 2
> -- note: this double cast is actually necessary
> return tonumber(ffi.cast('int16_t', ffi.cast('uint16_t', num)))
> @@ -403,8 +393,8 @@ end
> local decode_i32
> if strict_alignment then
> decode_i32 = function(data)
> - ffi.copy(tmpint, data[0], 4)
> - local num = bit.bswap(tonumber(tmpint[0].u32))
> + ffi.copy(scalar, data[0], 4)
> + local num = bit.bswap(tonumber(scalar.u32))
> data[0] = data[0] + 4
> return num
> end
> @@ -419,9 +409,9 @@ end
> local decode_i64
> if strict_alignment then
> decode_i64 = function(data)
> - ffi.copy(tmpint, data[0], 8)
> + ffi.copy(scalar, data[0], 8)
> data[0] = data[0] + 8
> - local num = bit.bswap(ffi.cast('int64_t', tmpint[0].u64))
> + local num = bit.bswap(scalar.i64)
> if num >= -DBL_INT_MAX and num <= DBL_INT_MAX then
> return tonumber(num) -- return as 'number'
> end
> @@ -552,7 +542,7 @@ end
> -- element. It is significally faster on LuaJIT to use double pointer than
> -- return result, newpos.
> --
> -local bufp = ffi.new('const unsigned char *[1]');
> +local bufp = scalar.acucp;
>
> local function check_offset(offset, len)
> if offset == nil then
> diff --git a/src/lua/socket.lua b/src/lua/socket.lua
> index b2700e0c0..1ddafee2f 100644
> --- a/src/lua/socket.lua
> +++ b/src/lua/socket.lua
> @@ -10,6 +10,9 @@ local fiber = require('fiber')
> local fio = require('fio')
> local log = require('log')
> local buffer = require('buffer')
> +local scalar = buffer.scalar
> +local scalar_array = buffer.scalar_array
> +local static_alloc = buffer.static_alloc
>
> local format = string.format
>
> @@ -472,9 +475,9 @@ local function socket_setsockopt(self, level, name, value)
> end
>
> if info.type == 1 then
> - local value = ffi.new("int[1]", value)
> + scalar.ai[0] = value
> local res = ffi.C.setsockopt(fd,
> - level, info.iname, value, ffi.sizeof('int'))
> + level, info.iname, scalar.ai, ffi.sizeof('int'))
>
> if res < 0 then
> self._errno = boxerrno()
> @@ -516,8 +519,10 @@ local function socket_getsockopt(self, level, name)
> self._errno = nil
>
> if info.type == 1 then
> - local value = ffi.new("int[1]", 0)
> - local len = ffi.new("size_t[1]", ffi.sizeof('int'))
> + local value = scalar_array[0].ai
> + value[0] = 0
> + local len = scalar_array[1].as
> + len[0] = ffi.sizeof('int')
> local res = ffi.C.getsockopt(fd, level, info.iname, value, len)
>
> if res < 0 then
> @@ -532,8 +537,9 @@ local function socket_getsockopt(self, level, name)
> end
>
> if info.type == 2 then
> - local value = ffi.new("char[256]", { 0 })
> - local len = ffi.new("size_t[1]", 256)
> + local value = static_alloc('char', 256)
> + local len = scalar.as
> + len[0] = 256
> local res = ffi.C.getsockopt(fd, level, info.iname, value, len)
> if res < 0 then
> self._errno = boxerrno()
> @@ -555,8 +561,9 @@ local function socket_linger(self, active, timeout)
> local info = internal.SO_OPT[level].SO_LINGER
> self._errno = nil
> if active == nil then
> - local value = ffi.new("linger_t[1]")
> - local len = ffi.new("size_t[1]", 2 * ffi.sizeof('int'))
> + local value = static_alloc('linger_t')
> + local len = scalar.as
> + len[0] = 2 * ffi.sizeof('linger_t')
> local res = ffi.C.getsockopt(fd, level, info.iname, value, len)
> if res < 0 then
> self._errno = boxerrno()
> @@ -581,9 +588,10 @@ local function socket_linger(self, active, timeout)
> iactive = 0
> end
>
> - local value = ffi.new("linger_t[1]",
> - { { active = iactive, timeout = timeout } })
> - local len = 2 * ffi.sizeof('int')
> + local value = static_alloc('linger_t')
> + value[0].active = iactive
> + value[0].timeout = timeout
> + local len = ffi.sizeof('linger_t')
> local res = ffi.C.setsockopt(fd, level, info.iname, value, len)
> if res < 0 then
> self._errno = boxerrno()
> @@ -798,8 +806,7 @@ local function get_recv_size(self, size)
> -- them using message peek.
> local iflags = get_iflags(internal.SEND_FLAGS, {'MSG_PEEK'})
> assert(iflags ~= nil)
> - local buf = ffi.new('char[?]', 1)
> - size = tonumber(ffi.C.recv(fd, buf, 1, iflags))
> + size = tonumber(ffi.C.recv(fd, scalar.ac, 1, iflags))
> -- Prevent race condition: proceed with the case when
> -- a datagram of length > 0 has been arrived after the
> -- getsockopt call above.
> @@ -836,8 +843,7 @@ local function socket_recv(self, size, flags)
> end
>
> self._errno = nil
> - local buf = ffi.new("char[?]", size)
> -
> + local buf = static_alloc('char', size)
> local res = ffi.C.recv(fd, buf, size, iflags)
>
> if res == -1 then
> diff --git a/src/lua/string.lua b/src/lua/string.lua
> index 8216ace6a..6ed6be8bf 100644
> --- a/src/lua/string.lua
> +++ b/src/lua/string.lua
> @@ -1,4 +1,6 @@
> local ffi = require('ffi')
> +local buffer = require('buffer')
> +local static_alloc = buffer.static_alloc
>
> ffi.cdef[[
> const char *
> @@ -13,8 +15,8 @@ ffi.cdef[[
> ]]
>
> local c_char_ptr = ffi.typeof('const char *')
> -local strip_newstart = ffi.new("unsigned long[1]")
> -local strip_newlen = ffi.new("unsigned long[1]")
> +local strip_newstart = buffer.scalar_array[0].aul
> +local strip_newlen = buffer.scalar_array[1].aul
>
> local memcmp = ffi.C.memcmp
> local memmem = ffi.C.memmem
> @@ -290,7 +292,7 @@ local function string_hex(inp)
> error(err_string_arg:format(1, 'string.hex', 'string', type(inp)), 2)
> end
> local len = inp:len() * 2
> - local res = ffi.new('char[?]', len + 1)
> + local res = static_alloc('char', len + 1)
>
> local uinp = ffi.cast('const unsigned char *', inp)
> for i = 0, inp:len() - 1 do
> @@ -333,7 +335,7 @@ local function string_fromhex(inp)
> end
> local len = inp:len() / 2
> local casted_inp = ffi.cast('const char *', inp)
> - local res = ffi.new('char[?]', len)
> + local res = static_alloc('char', len)
> for i = 0, len - 1 do
> local first = hexadecimals_mapping[casted_inp[i * 2]]
> local second = hexadecimals_mapping[casted_inp[i * 2 + 1]]
> diff --git a/src/lua/uri.lua b/src/lua/uri.lua
> index d2946cd2d..5967c8bf2 100644
> --- a/src/lua/uri.lua
> +++ b/src/lua/uri.lua
> @@ -1,6 +1,7 @@
> -- uri.lua (internal file)
>
> local ffi = require('ffi')
> +local static_alloc = require('buffer').static_alloc
>
> ffi.cdef[[
> struct uri {
> @@ -32,12 +33,11 @@ uri_format(char *str, size_t len, struct uri *uri, bool write_password);
>
> local builtin = ffi.C;
>
> -local uribuf = ffi.new('struct uri')
> -
> local function parse(str)
> if str == nil then
> error("Usage: uri.parse(string)")
> end
> + local uribuf = static_alloc('struct uri')
> if builtin.uri_parse(uribuf, str) ~= 0 then
> return nil
> end
> @@ -59,6 +59,7 @@ local function parse(str)
> end
>
> local function format(uri, write_password)
> + local uribuf = static_alloc('struct uri')
> uribuf.scheme = uri.scheme
> uribuf.scheme_len = string.len(uri.scheme or '')
> uribuf.login = uri.login
> @@ -75,7 +76,7 @@ local function format(uri, write_password)
> uribuf.query_len = string.len(uri.query or '')
> uribuf.fragment = uri.fragment
> uribuf.fragment_len = string.len(uri.fragment or '')
> - local str = ffi.new('char[1024]')
> + local str = static_alloc('char', 1024)
> builtin.uri_format(str, 1024, uribuf, write_password and 1 or 0)
> return ffi.string(str)
> end
> diff --git a/src/lua/uuid.lua b/src/lua/uuid.lua
> index 956ad6e36..f8418cf4d 100644
> --- a/src/lua/uuid.lua
> +++ b/src/lua/uuid.lua
> @@ -1,6 +1,7 @@
> -- uuid.lua (internal file)
>
> local ffi = require("ffi")
> +local static_alloc = require('buffer').static_alloc
> local builtin = ffi.C
>
> ffi.cdef[[
> @@ -33,7 +34,6 @@ extern const struct tt_uuid uuid_nil;
> local uuid_t = ffi.typeof('struct tt_uuid')
> local UUID_STR_LEN = 36
> local UUID_LEN = ffi.sizeof(uuid_t)
> -local uuidbuf = ffi.new(uuid_t)
>
> local uuid_tostring = function(uu)
> if not ffi.istype(uuid_t, uu) then
> @@ -69,9 +69,8 @@ local uuid_tobin = function(uu, byteorder)
> return error('Usage: uuid:bin([byteorder])')
> end
> if need_bswap(byteorder) then
> - if uu ~= uuidbuf then
> - ffi.copy(uuidbuf, uu, UUID_LEN)
> - end
> + local uuidbuf = static_alloc('struct tt_uuid')
> + ffi.copy(uuidbuf, uu, UUID_LEN)
> builtin.tt_uuid_bswap(uuidbuf)
> return ffi.string(ffi.cast('char *', uuidbuf), UUID_LEN)
> end
> @@ -114,10 +113,12 @@ local uuid_new = function()
> end
>
> local uuid_new_bin = function(byteorder)
> + local uuidbuf = static_alloc('struct tt_uuid')
> builtin.tt_uuid_create(uuidbuf)
> return uuid_tobin(uuidbuf, byteorder)
> end
> local uuid_new_str = function()
> + local uuidbuf = static_alloc('struct tt_uuid')
> builtin.tt_uuid_create(uuidbuf)
> return uuid_tostring(uuidbuf)
> end
> diff --git a/test/app/buffer.result b/test/app/buffer.result
> new file mode 100644
> index 000000000..10494b812
> --- /dev/null
> +++ b/test/app/buffer.result
> @@ -0,0 +1,53 @@
> +test_run = require('test_run').new()
> +---
> +...
> +buffer = require('buffer')
> +---
> +...
> +ffi = require('ffi')
> +---
> +...
> +-- Scalar.
> +scalar = buffer.scalar
> +---
> +...
> +scalar.u16 = 100
> +---
> +...
> +u16 = ffi.new('uint16_t[1]')
> +---
> +...
> +ffi.copy(u16, scalar, 2)
> +---
> +...
> +u16[0]
> +---
> +- 100
> +...
> +u16[0] = 200
> +---
> +...
> +ffi.copy(scalar, u16, 2)
> +---
> +...
> +scalar.u16
> +---
> +- 200
> +...
> +-- Alignment.
> +_ = buffer.static_alloc('char') -- This makes buffer pos unaligned.
> +---
> +...
> +p = buffer.static_alloc('int')
> +---
> +...
> +ffi.cast('int', p) % ffi.alignof('int') == 0 -- But next alloc is aligned.
> +---
> +- true
> +...
> +-- Able to allocate bigger than static buffer - such allocations
> +-- are on the heap.
> +type(buffer.static_alloc('char', 13000))
> +---
> +- cdata
> +...
> diff --git a/test/app/buffer.test.lua b/test/app/buffer.test.lua
> new file mode 100644
> index 000000000..6b1a974ca
> --- /dev/null
> +++ b/test/app/buffer.test.lua
> @@ -0,0 +1,23 @@
> +test_run = require('test_run').new()
> +buffer = require('buffer')
> +ffi = require('ffi')
> +
> +-- Scalar.
> +scalar = buffer.scalar
> +scalar.u16 = 100
> +u16 = ffi.new('uint16_t[1]')
> +ffi.copy(u16, scalar, 2)
> +u16[0]
> +
> +u16[0] = 200
> +ffi.copy(scalar, u16, 2)
> +scalar.u16
> +
> +-- Alignment.
> +_ = buffer.static_alloc('char') -- This makes buffer pos unaligned.
> +p = buffer.static_alloc('int')
> +ffi.cast('int', p) % ffi.alignof('int') == 0 -- But next alloc is aligned.
> +
> +-- Able to allocate bigger than static buffer - such allocations
> +-- are on the heap.
> +type(buffer.static_alloc('char', 13000))
>
More information about the Tarantool-patches
mailing list