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/*
*
* Copyright 2015 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include "src/core/lib/transport/timeout_encoding.h"
#include <stdio.h>
#include <string.h>
#include <grpc/support/port_platform.h>
#include "src/core/lib/gpr/string.h"
static int64_t round_up(int64_t x, int64_t divisor) {
return (x / divisor + (x % divisor != 0)) * divisor;
}
/* round an integer up to the next value with three significant figures */
static int64_t round_up_to_three_sig_figs(int64_t 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) { memcpy(buffer, "1n", 3); }
static void enc_ext(char* buffer, int64_t value, char ext) {
int n = int64_ttoa(value, buffer);
buffer[n] = ext;
buffer[n + 1] = 0;
}
static void enc_seconds(char* buffer, int64_t sec) {
if (sec % 3600 == 0) {
enc_ext(buffer, sec / 3600, 'H');
} else if (sec % 60 == 0) {
enc_ext(buffer, sec / 60, 'M');
} else {
enc_ext(buffer, sec, 'S');
}
}
static void enc_millis(char* buffer, int64_t x) {
x = round_up_to_three_sig_figs(x);
if (x < GPR_MS_PER_SEC) {
enc_ext(buffer, x, 'm');
} else {
if (x % GPR_MS_PER_SEC == 0) {
enc_seconds(buffer, x / GPR_MS_PER_SEC);
} else {
enc_ext(buffer, x, 'm');
}
}
}
void grpc_http2_encode_timeout(grpc_millis timeout, char* buffer) {
if (timeout <= 0) {
enc_tiny(buffer);
} else if (timeout < 1000 * GPR_MS_PER_SEC) {
enc_millis(buffer, timeout);
} else {
enc_seconds(buffer,
timeout / GPR_MS_PER_SEC + (timeout % GPR_MS_PER_SEC != 0));
}
}
static int is_all_whitespace(const char* p, const char* end) {
while (p != end && *p == ' ') p++;
return p == end;
}
int grpc_http2_decode_timeout(grpc_slice text, grpc_millis* timeout) {
grpc_millis x = 0;
const uint8_t* p = GRPC_SLICE_START_PTR(text);
const uint8_t* end = GRPC_SLICE_END_PTR(text);
int have_digit = 0;
/* skip whitespace */
for (; p != end && *p == ' '; p++)
;
/* decode numeric part */
for (; p != end && *p >= '0' && *p <= '9'; p++) {
int32_t digit = (int32_t)(*p - (uint8_t)'0');
have_digit = 1;
/* spec allows max. 8 digits, but we allow values up to 1,000,000,000 */
if (x >= (100 * 1000 * 1000)) {
if (x != (100 * 1000 * 1000) || digit != 0) {
*timeout = GRPC_MILLIS_INF_FUTURE;
return 1;
}
}
x = x * 10 + digit;
}
if (!have_digit) return 0;
/* skip whitespace */
for (; p != end && *p == ' '; p++)
;
if (p == end) return 0;
/* decode unit specifier */
switch (*p) {
case 'n':
*timeout = x / GPR_NS_PER_MS + (x % GPR_NS_PER_MS != 0);
break;
case 'u':
*timeout = x / GPR_US_PER_MS + (x % GPR_US_PER_MS != 0);
break;
case 'm':
*timeout = x;
break;
case 'S':
*timeout = x * GPR_MS_PER_SEC;
break;
case 'M':
*timeout = x * 60 * GPR_MS_PER_SEC;
break;
case 'H':
*timeout = x * 60 * 60 * GPR_MS_PER_SEC;
break;
default:
return 0;
}
p++;
return is_all_whitespace((const char*)p, (const char*)end);
}
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