logd: liblog: logcat: Arbitrary time to tail
Change-Id: I10e8d92c933e31ee11e78d2d1114261a30c4be0e
diff --git a/liblog/log_time.cpp b/liblog/log_time.cpp
new file mode 100644
index 0000000..755c2d9
--- /dev/null
+++ b/liblog/log_time.cpp
@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * 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 <ctype.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/cdefs.h>
+
+#include <log/log_read.h>
+
+const char log_time::default_format[] = "%m-%d %H:%M:%S.%3q";
+const timespec log_time::EPOCH = { 0, 0 };
+
+// Add %#q for fractional seconds to standard strptime function
+
+char *log_time::strptime(const char *s, const char *format) {
+ time_t now;
+#ifdef __linux__
+ *this = log_time(CLOCK_REALTIME);
+ now = tv_sec;
+#else
+ time(&now);
+ tv_sec = now;
+ tv_nsec = 0;
+#endif
+
+ struct tm *ptm;
+#if (defined(HAVE_LOCALTIME_R))
+ struct tm tmBuf;
+ ptm = localtime_r(&now, &tmBuf);
+#else
+ ptm = localtime(&now);
+#endif
+
+ char fmt[strlen(format) + 1];
+ strcpy(fmt, format);
+
+ char *ret = const_cast<char *> (s);
+ char *cp;
+ for (char *f = cp = fmt; ; ++cp) {
+ if (!*cp) {
+ if (f != cp) {
+ ret = ::strptime(ret, f, ptm);
+ }
+ break;
+ }
+ if (*cp != '%') {
+ continue;
+ }
+ char *e = cp;
+ ++e;
+#if (defined(__BIONIC__))
+ if (*e == 's') {
+ *cp = '\0';
+ if (*f) {
+ ret = ::strptime(ret, f, ptm);
+ if (!ret) {
+ break;
+ }
+ }
+ tv_sec = 0;
+ while (isdigit(*ret)) {
+ tv_sec = tv_sec * 10 + *ret - '0';
+ ++ret;
+ }
+ now = tv_sec;
+#if (defined(HAVE_LOCALTIME_R))
+ ptm = localtime_r(&now, &tmBuf);
+#else
+ ptm = localtime(&now);
+#endif
+ } else
+#endif
+ {
+ unsigned num = 0;
+ while (isdigit(*e)) {
+ num = num * 10 + *e - '0';
+ ++e;
+ }
+ if (*e != 'q') {
+ continue;
+ }
+ *cp = '\0';
+ if (*f) {
+ ret = ::strptime(ret, f, ptm);
+ if (!ret) {
+ break;
+ }
+ }
+ unsigned long mul = NS_PER_SEC;
+ if (num == 0) {
+ num = INT_MAX;
+ }
+ tv_nsec = 0;
+ while (isdigit(*ret) && num && (mul > 1)) {
+ --num;
+ mul /= 10;
+ tv_nsec = tv_nsec + (*ret - '0') * mul;
+ ++ret;
+ }
+ }
+ f = cp = e;
+ ++f;
+ }
+
+ if (ret) {
+ tv_sec = mktime(ptm);
+ return ret;
+ }
+
+ // Upon error, place a known value into the class, the current time.
+#ifdef __linux__
+ *this = log_time(CLOCK_REALTIME);
+#else
+ time(&now);
+ tv_sec = now;
+ tv_nsec = 0;
+#endif
+ return ret;
+}
+
+log_time log_time::operator-= (const timespec &T) {
+ // No concept of negative time, clamp to EPOCH
+ if (*this <= T) {
+ return *this = EPOCH;
+ }
+
+ if (this->tv_nsec < (unsigned long int)T.tv_nsec) {
+ --this->tv_sec;
+ this->tv_nsec = NS_PER_SEC + this->tv_nsec - T.tv_nsec;
+ } else {
+ this->tv_nsec -= T.tv_nsec;
+ }
+ this->tv_sec -= T.tv_sec;
+
+ return *this;
+}
+
+log_time log_time::operator-= (const log_time &T) {
+ // No concept of negative time, clamp to EPOCH
+ if (*this <= T) {
+ return *this = EPOCH;
+ }
+
+ if (this->tv_nsec < T.tv_nsec) {
+ --this->tv_sec;
+ this->tv_nsec = NS_PER_SEC + this->tv_nsec - T.tv_nsec;
+ } else {
+ this->tv_nsec -= T.tv_nsec;
+ }
+ this->tv_sec -= T.tv_sec;
+
+ return *this;
+}