logd: optimize code hotspots
Discovered that we had a few libc hotspots. Adjust code to generally
reduce or nullify the number of calls to malloc, free, strlen,
strcmp, strncmp, memcmp & strncasecmp. Total gain looks to be about
3% of logd's processing time. malloc still contributes to 3%, but all
others are now total 0.5%.
Bug: 23685592
Change-Id: Ife721121667969260cdb8b055524ae90f5911278
diff --git a/logd/LogBufferElement.cpp b/logd/LogBufferElement.cpp
index 9fb1439..150ce22 100644
--- a/logd/LogBufferElement.cpp
+++ b/logd/LogBufferElement.cpp
@@ -91,7 +91,8 @@
size_t retval_len = strlen(retval);
size_t name_len = strlen(name);
// KISS: ToDo: Only checks prefix truncated, not suffix, or both
- if ((retval_len < name_len) && !strcmp(retval, name + name_len - retval_len)) {
+ if ((retval_len < name_len)
+ && !fast<strcmp>(retval, name + name_len - retval_len)) {
free(retval);
retval = name;
} else {
@@ -123,14 +124,16 @@
commName = parent->pidToName(mPid);
parent->unlock();
}
- size_t len = name ? strlen(name) : 0;
- if (len && commName && !strncmp(name, commName, len)) {
- if (commName[len] == '\0') {
- free(commName);
- commName = NULL;
- } else {
- free(name);
- name = NULL;
+ if (name && name[0] && commName && (name[0] == commName[0])) {
+ size_t len = strlen(name + 1);
+ if (!strncmp(name + 1, commName + 1, len)) {
+ if (commName[len + 1] == '\0') {
+ free(commName);
+ commName = NULL;
+ } else {
+ free(name);
+ name = NULL;
+ }
}
}
if (name) {
@@ -150,9 +153,9 @@
}
}
// identical to below to calculate the buffer size required
- len = snprintf(NULL, 0, format_uid, mUid, name ? name : "",
- commName ? commName : "",
- mDropped, (mDropped > 1) ? "s" : "");
+ size_t len = snprintf(NULL, 0, format_uid, mUid, name ? name : "",
+ commName ? commName : "",
+ mDropped, (mDropped > 1) ? "s" : "");
size_t hdrLen;
if (mLogId == LOG_ID_EVENTS) {