From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: [tarantool-patches] [PATCH v1 1/1] implement mp_stack class References: <9613f79e65d9838763422aae0bfb3ca9e2901a32.1547645639.git.kshcherbatov@gmail.com> From: Kirill Shcherbatov Message-ID: <5d8645a5-3607-3d8d-3737-eadaf1194b0c@tarantool.org> Date: Thu, 17 Jan 2019 10:32:32 +0300 MIME-Version: 1.0 In-Reply-To: <9613f79e65d9838763422aae0bfb3ca9e2901a32.1547645639.git.kshcherbatov@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit To: tarantool-patches@freelists.org, Vladimir Davydov Cc: Kostya Osipov List-ID: https://github.com/tarantool/tarantool/tree/kshch/gh-1012-msgpuck-class Introduced a new mp_stack class to make complex msgpack parsing. The structure is needed in order to facilitate the decoding nested MP_ARRAY and MP_MAP msgpack containers without recursion. This allows you to determine that the parsing of the current container is complete. Needed for #1012 --- msgpuck.h | 130 +++++++++++++++++++++++++++++++++++++++++++++++++ test/msgpuck.c | 59 +++++++++++++++++++++- 2 files changed, 188 insertions(+), 1 deletion(-) diff --git a/msgpuck.h b/msgpuck.h index b0d4967..a12eca9 100644 --- a/msgpuck.h +++ b/msgpuck.h @@ -359,6 +359,45 @@ enum mp_type { MP_EXT }; +/** Message pack MP_MAP or MP_ARRAY container descriptor. */ +struct mp_frame { + /** MP frame type calculated with mp_typeof(). */ + enum mp_type type; + /** + * Total items in MP_MAP or MP_ARRAY container + * calculated with mp_decode_map() or mp_decode_array(). + */ + uint32_t size; + /** + * Count of items already processed. Must be less or + * equal to mp_frame::size member. + */ + uint32_t curr; +}; + +/** + * Stack of service contexts mp_frame to do complex msgpack parse. + * The structure is needed in order to facilitate the decoding + * nested MP_ARRAY and MP_MAP msgpack containers without + * recursion. This allows you to determine that the parsing of + * the current container is complete. +*/ +struct mp_stack { + /** The maximum stack depth. */ + uint32_t size; + /** + * Count of used stack frames. Corresponds to the index + * in the array to perform the push operation. Must be + * less or equal to mp_stack::size member. + */ + uint32_t used; + /** + * Array of mp_frames descriptors having at least + * mp_stack::size items. + */ + struct mp_frame *frames; +}; + /** * \brief Determine MsgPack type by a first byte \a c of encoded data. * @@ -1184,6 +1223,97 @@ mp_check(const char **data, const char *end); * {{{ Implementation */ +/** + * \brief Initialize mp_stack \stack of specified size \size and + * user-allocated array \frames. + * The \frames allocation must have at least \size mp_frame items. + * \param stack - the pointer to a mp_stack to initialize. + * \param size - stack size, count of stack::frames to use. + * \param frames - mp_frame service context allocation to use, + * must have at least \size items. + */ +MP_PROTO void +mp_stack_init(struct mp_stack *stack, uint32_t size, struct mp_frame *frames) +{ + stack->frames = frames; + stack->size = size; + stack->used = 0; +} + +/** + * \brief Test if mp_stack \stack is empty. + * \param stack - the pointer to a mp_stack to a stack to test. + */ +MP_PROTO bool +mp_stack_is_empty(struct mp_stack *stack) +{ + return stack->used == 0; +} + +/** + * \brief Test if mp_stack \stack is full. + * \param stack - the pointer to a mp_stack to a stack to test. + */ +MP_PROTO bool +mp_stack_is_full(struct mp_stack *stack) +{ + return stack->used >= stack->size; +} + +/** + * \brief Pop the top mp_stack \stack frame. + * \stack must not be empty. + * \param stack - the pointer to a mp_stack to operate with. + */ +MP_PROTO void +mp_stack_pop(struct mp_stack *stack) +{ + assert(!mp_stack_is_empty(stack)); + --stack->used; +} + +/** + * \brief Get a pointer to a top mp_stack \stack frame. + * \param stack - the pointer to a mp_stack to operate with. + * The \stack must not be empty. + * \retval a pointer to a top stack frame. + */ +MP_PROTO struct mp_frame * +mp_stack_top(struct mp_stack *stack) +{ + assert(!mp_stack_is_empty(stack)); + return &stack->frames[stack->used - 1]; +} + +/** + * \brief Construct a new mp_frame and push it on to mp_stack + * \stack. The \stack must not be full. + * \param stack - the pointer to a stack to operate with. + * \retval a pointer to a top stack frame. + */ +MP_PROTO void +mp_stack_push(struct mp_stack *stack, enum mp_type type, uint32_t size) +{ + assert(!mp_stack_is_full(stack)); + uint32_t idx = stack->used++; + stack->frames[idx].type = type; + stack->frames[idx].size = size; + stack->frames[idx].curr = 0; +} + +/** + * \brief Advance a mp_stack::curr attribute of the mp_stack. + * \stack top frame. The \stack must not be empty. + * \retval true, when the top frame have already parsed: + * mp_stack::curr >= mp_stack::size; false otherwise. + */ +MP_PROTO bool +mp_stack_advance(struct mp_stack *stack) +{ + struct mp_frame *frame = mp_stack_top(stack); + return ++frame->curr > frame->size; +} + /** \cond false */ extern const enum mp_type mp_type_hint[]; extern const int8_t mp_parser_hint[]; diff --git a/test/msgpuck.c b/test/msgpuck.c index 9265453..fe6aa47 100644 --- a/test/msgpuck.c +++ b/test/msgpuck.c @@ -1093,10 +1093,66 @@ test_overflow() return check_plan(); } +static int +test_mpstack() +{ + plan(18); + header(); + + char tuple[1024]; + char *wptr = tuple; + /* ["first", {"key1": 1, "key2": [1]}, [1]] */ + wptr = mp_encode_array(wptr, 3); + wptr = mp_encode_str(wptr, "first", 5); + wptr = mp_encode_map(wptr, 2); + wptr = mp_encode_str(wptr, "key1", 4); + wptr = mp_encode_uint(wptr, 1); + wptr = mp_encode_str(wptr, "key2", 4); + wptr = mp_encode_array(wptr, 1); + wptr = mp_encode_uint(wptr, 1); + wptr = mp_encode_array(wptr, 1); + wptr = mp_encode_uint(wptr, 1); + const char *rptr = tuple; + + struct mp_frame mp_frames[2]; + struct mp_stack mp_stack; + mp_stack_init(&mp_stack, 2, mp_frames); + is(mp_stack_is_empty(&mp_stack), true, "Stack is empty"); + mp_stack_push(&mp_stack, MP_ARRAY, mp_decode_array(&rptr)); + is(mp_stack_is_empty(&mp_stack), false, "Stack is not empty"); + is(mp_stack_is_full(&mp_stack), false, "Stack is not full"); + is(mp_stack_top(&mp_stack)->type, MP_ARRAY, "Correct field type"); + is(mp_stack_top(&mp_stack)->size, 3, "Correct items count"); + is(mp_stack_advance(&mp_stack), false, "Not all items on level 1 parsed"); + mp_next(&rptr); + is(mp_stack_top(&mp_stack)->curr, 1, "Correct current item index"); + mp_stack_push(&mp_stack, MP_MAP, mp_decode_map(&rptr)); + is(mp_stack_top(&mp_stack)->type, MP_MAP, "Correct field type"); + is(mp_stack_top(&mp_stack)->size, 2, "Correct items count"); + is(mp_stack_is_full(&mp_stack), true, "Stack is full"); + is(mp_stack_advance(&mp_stack), false, "Not all items on level 2 parsed"); + mp_next(&rptr); + mp_next(&rptr); + is(mp_stack_advance(&mp_stack), false, "Not all items on level 2 parsed"); + is(mp_stack_advance(&mp_stack), true, "All items on level 2 parsed"); + mp_next(&rptr); + mp_next(&rptr); + mp_stack_pop(&mp_stack); + is(mp_stack_is_full(&mp_stack), false, "Stack is not full"); + is(mp_stack_advance(&mp_stack), false, "Not all items on level 1 parsed"); + mp_next(&rptr); + is(mp_stack_advance(&mp_stack), false, "Not all items on level 1 parsed"); + is(mp_stack_advance(&mp_stack), true, "All items on level 1 parsed"); + mp_stack_pop(&mp_stack); + is(mp_stack_is_empty(&mp_stack), true, "Stack is empty"); + + footer(); + return check_plan(); +} int main() { - plan(20); + plan(21); test_uints(); test_ints(); test_bools(); @@ -1117,6 +1173,7 @@ int main() test_mp_check(); test_numbers(); test_overflow(); + test_mpstack(); return check_plan(); } -- 2.19.2