diff options
Diffstat (limited to 'src/core/transport/chttp2/timeout_encoding.c')
| -rw-r--r-- | src/core/transport/chttp2/timeout_encoding.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/src/core/transport/chttp2/timeout_encoding.c b/src/core/transport/chttp2/timeout_encoding.c new file mode 100644 index 0000000000..2706c369a6 --- /dev/null +++ b/src/core/transport/chttp2/timeout_encoding.c @@ -0,0 +1,176 @@ +/* + * + * Copyright 2014, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * 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. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "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 THE COPYRIGHT + * OWNER 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 "src/core/transport/chttp2/timeout_encoding.h" + +#include <stdio.h> +#include <string.h> + +static int round_up(int x, int divisor) { + return (x / divisor + (x % divisor != 0)) * divisor; +} + +/* round an integer up to the next value with three significant figures */ +static int round_up_to_three_sig_figs(int x) { + if (x < 1000) return x; + if (x < 10000) return round_up(x, 10); + if (x < 100000) return round_up(x, 100); + if (x < 1000000) return round_up(x, 1000); + if (x < 10000000) return round_up(x, 10000); + if (x < 100000000) return round_up(x, 100000); + if (x < 1000000000) return round_up(x, 1000000); + return round_up(x, 10000000); +} + +/* encode our minimum viable timeout value */ +static void enc_tiny(char *buffer) { strcpy(buffer, "1n"); } + +static void enc_seconds(char *buffer, long sec) { + if (sec % 3600 == 0) { + sprintf(buffer, "%ldH", sec / 3600); + } else if (sec % 60 == 0) { + sprintf(buffer, "%ldM", sec / 60); + } else { + sprintf(buffer, "%ldS", sec); + } +} + +static void enc_nanos(char *buffer, int x) { + x = round_up_to_three_sig_figs(x); + if (x < 100000) { + if (x % 1000 == 0) { + sprintf(buffer, "%du", x / 1000); + } else { + sprintf(buffer, "%dn", x); + } + } else if (x < 100000000) { + if (x % 1000000 == 0) { + sprintf(buffer, "%dm", x / 1000000); + } else { + sprintf(buffer, "%du", x / 1000); + } + } else if (x < 1000000000) { + sprintf(buffer, "%dm", x / 1000000); + } else { + /* note that this is only ever called with times of less than one second, + so if we reach here the time must have been rounded up to a whole second + (and no more) */ + strcpy(buffer, "1S"); + } +} + +static void enc_micros(char *buffer, int x) { + x = round_up_to_three_sig_figs(x); + if (x < 100000) { + if (x % 1000 == 0) { + sprintf(buffer, "%dm", x / 1000); + } else { + sprintf(buffer, "%du", x); + } + } else if (x < 100000000) { + if (x % 1000000 == 0) { + sprintf(buffer, "%dS", x / 1000000); + } else { + sprintf(buffer, "%dm", x / 1000); + } + } else { + sprintf(buffer, "%dS", x / 1000000); + } +} + +void grpc_chttp2_encode_timeout(gpr_timespec timeout, char *buffer) { + if (timeout.tv_sec < 0) { + enc_tiny(buffer); + } else if (timeout.tv_sec == 0) { + enc_nanos(buffer, timeout.tv_nsec); + } else if (timeout.tv_sec < 1000 && timeout.tv_nsec != 0) { + enc_micros(buffer, + timeout.tv_sec * 1000000 + + (timeout.tv_nsec / 1000 + (timeout.tv_nsec % 1000 != 0))); + } else { + enc_seconds(buffer, timeout.tv_sec + (timeout.tv_nsec != 0)); + } +} + +static int is_all_whitespace(const char *p) { + while (*p == ' ') p++; + return *p == 0; +} + +int grpc_chttp2_decode_timeout(const char *buffer, gpr_timespec *timeout) { + gpr_uint32 x = 0; + const char *p = buffer; + int have_digit = 0; + /* skip whitespace */ + for (; *p == ' '; p++) + ; + /* decode numeric part */ + for (; *p >= '0' && *p <= '9'; p++) { + gpr_uint32 xp = x * 10 + *p - '0'; + have_digit = 1; + if (xp < x) { + *timeout = gpr_inf_future; + return 1; + } + x = xp; + } + if (!have_digit) return 0; + /* skip whitespace */ + for (; *p == ' '; p++) + ; + /* decode unit specifier */ + switch (*p) { + case 'n': + *timeout = gpr_time_from_nanos(x); + break; + case 'u': + *timeout = gpr_time_from_micros(x); + break; + case 'm': + *timeout = gpr_time_from_millis(x); + break; + case 'S': + *timeout = gpr_time_from_seconds(x); + break; + case 'M': + *timeout = gpr_time_from_minutes(x); + break; + case 'H': + *timeout = gpr_time_from_hours(x); + break; + default: + return 0; + } + p++; + return is_all_whitespace(p); +} |