From: Sergey Nikiforov <void@tarantool.org> To: tarantool-patches@dev.tarantool.org Cc: Vladislav Shpilevoy <v.shpilevoy@tarantool.org> Subject: [Tarantool-patches] [PATCH v5 2/2] base64: improve decoder performance Date: Fri, 25 Dec 2020 13:41:05 +0300 [thread overview] Message-ID: <e4f48da72d6794a212a8fc908e30a197a9f7ba9b.1608892639.git.void234@gmail.com> (raw) In-Reply-To: <cover.1608892639.git.void234@gmail.com> 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). --- 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 3350a98ff..2b2b61ba4 100644 --- a/third_party/base64.c +++ b/third_party/base64.c @@ -257,10 +257,10 @@ 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++); @@ -268,7 +268,7 @@ 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; @@ -276,14 +276,19 @@ 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; @@ -291,14 +296,19 @@ 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; @@ -306,6 +316,13 @@ 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:[~2020-12-25 10:41 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-12-25 10:41 [Tarantool-patches] [PATCH v5 0/2] base64: Fix decoder, improve its performance Sergey Nikiforov 2020-12-25 10:41 ` [Tarantool-patches] [PATCH v5 1/2] base64: fix decoder output buffer overrun (reads) Sergey Nikiforov 2020-12-25 13:00 ` Leonid Vasiliev 2020-12-25 10:41 ` Sergey Nikiforov [this message] 2020-12-25 13:01 ` [Tarantool-patches] [PATCH v5 2/2] base64: improve decoder performance Leonid Vasiliev 2020-12-25 13:08 ` [Tarantool-patches] [PATCH v5 0/2] base64: Fix decoder, improve its performance Leonid Vasiliev 2020-12-25 14:09 Sergey Nikiforov 2020-12-25 14:09 ` [Tarantool-patches] [PATCH v5 2/2] base64: improve decoder performance Sergey Nikiforov
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