Reland "Delete STACK_ARRAY macro, and use of alloca"
This is a reland of 74b373f04a69b279e45b0792d86c594cb33d22c1
Original change's description:
> Delete STACK_ARRAY macro, and use of alloca
>
> Refactor the few uses of STACK_ARRAY to avoid an extra copy
> on the stack.
>
> Bug: webrtc:6424
> Change-Id: I5c8f3c0381523db0ead31207d949df9a286c76ba
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/137806
> Commit-Queue: Niels Moller <nisse@webrtc.org>
> Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#28038}
Bug: webrtc:6424
Change-Id: Id635ccdfae12157cbb3ab9089c5e4a9f77f742ce
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/138211
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28052}
diff --git a/rtc_base/string_encode.cc b/rtc_base/string_encode.cc
index 7b2eda7..da31ac0 100644
--- a/rtc_base/string_encode.cc
+++ b/rtc_base/string_encode.cc
@@ -14,7 +14,6 @@
#include "rtc_base/arraysize.h"
#include "rtc_base/checks.h"
-#include "rtc_base/string_utils.h"
namespace rtc {
@@ -45,25 +44,22 @@
return true;
}
-// hex_encode, but separate each byte representation with a delimiter.
-// |delimiter| == 0 means no delimiter
-// If the buffer is too short, we return 0
-size_t hex_encode_with_delimiter(char* buffer,
- size_t buflen,
- const char* csource,
- size_t srclen,
- char delimiter) {
- RTC_DCHECK(buffer); // TODO(kwiberg): estimate output size
- if (buflen == 0)
- return 0;
+size_t hex_encode_output_length(size_t srclen, char delimiter) {
+ return delimiter && srclen > 0 ? (srclen * 3 - 1) : (srclen * 2);
+}
+
+// hex_encode shows the hex representation of binary data in ascii, with
+// |delimiter| between bytes, or none if |delimiter| == 0.
+void hex_encode_with_delimiter(char* buffer,
+ const char* csource,
+ size_t srclen,
+ char delimiter) {
+ RTC_DCHECK(buffer);
// Init and check bounds.
const unsigned char* bsource =
reinterpret_cast<const unsigned char*>(csource);
size_t srcpos = 0, bufpos = 0;
- size_t needed = delimiter ? (srclen * 3) : (srclen * 2 + 1);
- if (buflen < needed)
- return 0;
while (srcpos < srclen) {
unsigned char ch = bsource[srcpos++];
@@ -77,10 +73,6 @@
++bufpos;
}
}
-
- // Null terminate.
- buffer[bufpos] = '\0';
- return bufpos;
}
} // namespace
@@ -96,12 +88,11 @@
std::string hex_encode_with_delimiter(const char* source,
size_t srclen,
char delimiter) {
- const size_t kBufferSize = srclen * 3;
- char* buffer = STACK_ARRAY(char, kBufferSize);
- size_t length =
- hex_encode_with_delimiter(buffer, kBufferSize, source, srclen, delimiter);
- RTC_DCHECK(srclen == 0 || length > 0);
- return std::string(buffer, length);
+ std::string s(hex_encode_output_length(srclen, delimiter), 0);
+ // TODO(nisse): When we can use C++17, switch the below hack with begin to
+ // just s.data().
+ hex_encode_with_delimiter(&*s.begin(), source, srclen, delimiter);
+ return s;
}
size_t hex_decode(char* cbuffer,