From: Sergey Nikiforov via Tarantool-patches <tarantool-patches@dev.tarantool.org> To: tarantool-patches@dev.tarantool.org Cc: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>, Alexander Turenko <alexander.turenko@tarantool.org> Subject: [Tarantool-patches] [PATCH v6 2/2] base64: improve decoder performance Date: Mon, 11 Jan 2021 12:45:01 +0300 [thread overview] Message-ID: <b3f6a37aef7bc59668e9f1e6b9638920a8f52846.1610357625.git.void@tarantool.org> (raw) In-Reply-To: <cover.1610357625.git.void@tarantool.org> Unnecessary checks were removed from internal loops. Benchmark shows that performance is now ~1.19 times higher (release build, Intel Core I7-9700K, only one thread). --- Branch: https://github.com/tarantool/tarantool/tree/void234/gh-3069-fix-base64-memory-overrun-v6 third_party/base64.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/third_party/base64.c b/third_party/base64.c index 3ecd0843a..74260971b 100644 --- a/third_party/base64.c +++ b/third_party/base64.c @@ -258,10 +258,10 @@ base64_decode_block(const char *in_base64, int in_len, { case step_a: do { - if (in_pos == in_end || out_pos >= out_end) + if (in_pos >= in_end) { state->step = step_a; - state->result = curr_byte; + /* curr_byte is useless now. */ return out_pos - out_bin; } fragment = base64_decode_value(*in_pos++); @@ -269,7 +269,7 @@ base64_decode_block(const char *in_base64, int in_len, curr_byte = (fragment & 0x03f) << 2; case step_b: do { - if (in_pos == in_end || out_pos >= out_end) + if (in_pos >= in_end) { state->step = step_b; state->result = curr_byte; @@ -277,14 +277,19 @@ base64_decode_block(const char *in_base64, int in_len, } fragment = base64_decode_value(*in_pos++); } while (fragment < 0); + if (out_pos >= out_end) + { + /* We are losing some data. */ + state->step = step_b; + state->result = curr_byte; + return out_pos - out_bin; + } curr_byte |= (fragment & 0x030) >> 4; *out_pos++ = curr_byte; curr_byte = (fragment & 0x00f) << 4; - if (out_pos < out_end) - *out_pos = curr_byte; case step_c: do { - if (in_pos == in_end || out_pos >= out_end) + if (in_pos >= in_end) { state->step = step_c; state->result = curr_byte; @@ -292,14 +297,19 @@ base64_decode_block(const char *in_base64, int in_len, } fragment = base64_decode_value(*in_pos++); } while (fragment < 0); + if (out_pos >= out_end) + { + /* We are losing some data. */ + state->step = step_c; + state->result = curr_byte; + return out_pos - out_bin; + } curr_byte |= (fragment & 0x03c) >> 2; *out_pos++ = curr_byte; curr_byte = (fragment & 0x003) << 6; - if (out_pos < out_end) - *out_pos = curr_byte; case step_d: do { - if (in_pos == in_end || out_pos >= out_end) + if (in_pos >= in_end) { state->step = step_d; state->result = curr_byte; @@ -307,6 +317,13 @@ base64_decode_block(const char *in_base64, int in_len, } fragment = base64_decode_value(*in_pos++); } while (fragment < 0); + if (out_pos >= out_end) + { + /* We are losing some data. */ + state->step = step_d; + state->result = curr_byte; + return out_pos - out_bin; + } curr_byte |= (fragment & 0x03f); *out_pos++ = curr_byte; } -- 2.25.1
next prev parent reply other threads:[~2021-01-11 9:46 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-01-11 9:44 [Tarantool-patches] [PATCH v6 0/2] base64: Fix decoder, improve its performance Sergey Nikiforov via Tarantool-patches 2021-01-11 9:45 ` [Tarantool-patches] [PATCH v6 1/2] base64: fix decoder output buffer overrun (reads) Sergey Nikiforov via Tarantool-patches 2021-01-21 2:16 ` Alexander Turenko via Tarantool-patches 2021-01-26 16:37 ` Sergey Nikiforov via Tarantool-patches 2021-01-26 16:48 ` Sergey Nikiforov via Tarantool-patches 2021-02-20 11:30 ` Alexander Turenko via Tarantool-patches 2021-02-20 12:49 ` Alexander Turenko via Tarantool-patches 2021-02-25 8:25 ` Sergey Nikiforov via Tarantool-patches 2021-02-27 18:47 ` Alexander Turenko via Tarantool-patches 2021-01-11 9:45 ` Sergey Nikiforov via Tarantool-patches [this message] 2021-01-21 15:31 ` [Tarantool-patches] [PATCH v6 2/2] base64: improve decoder performance Alexander Turenko via Tarantool-patches 2021-01-26 16:37 ` Sergey Nikiforov via Tarantool-patches 2021-02-20 12:51 ` Alexander Turenko via Tarantool-patches 2021-01-12 19:39 ` [Tarantool-patches] [PATCH v6 0/2] base64: Fix decoder, improve its performance Alexander Turenko via Tarantool-patches
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