From 05227d99e0c66d6236190a9c37f060559cb58493 Mon Sep 17 00:00:00 2001
From: Yurii Zubrytskyi <zyy@google.com>
Date: Fri, 20 Mar 2020 22:39:23 -0700
Subject: [PATCH] [adb] file sync performance on Windows

Print not more often than once a 100ms - it is smooth enough
and speeds up transfer even more on Windows, where a single
line output may take up to 5ms.
An added benefit is getting rid of some extra heap allocation
and string formatting when in the end the identical message
filtering would've dropped the line anyway. This is also
significantly more expensive on Windows.

Bug: 151900478
Test: manual, push/pull a file and a directory

Change-Id: I9038729e8a01d5f93fd301beaeb8a086f5039b77
---
 adb/client/file_sync_client.cpp | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/adb/client/file_sync_client.cpp b/adb/client/file_sync_client.cpp
index 94bd8f543..f29ca9288 100644
--- a/adb/client/file_sync_client.cpp
+++ b/adb/client/file_sync_client.cpp
@@ -53,6 +53,8 @@
 #include <android-base/strings.h>
 #include <android-base/stringprintf.h>
 
+using namespace std::literals;
+
 typedef void(sync_ls_cb)(unsigned mode, uint64_t size, uint64_t time, const char* name);
 
 struct syncsendbuf {
@@ -112,8 +114,12 @@ struct TransferLedger {
     uint64_t bytes_transferred;
     uint64_t bytes_expected;
     bool expect_multiple_files;
-    std::string last_progress_str;
 
+  private:
+    std::string last_progress_str;
+    std::chrono::steady_clock::time_point last_progress_time;
+
+  public:
     TransferLedger() {
         Reset();
     }
@@ -128,12 +134,13 @@ struct TransferLedger {
     }
 
     void Reset() {
-        last_progress_str.clear();
         start_time = std::chrono::steady_clock::now();
         files_transferred = 0;
         files_skipped = 0;
         bytes_transferred = 0;
         bytes_expected = 0;
+        last_progress_str.clear();
+        last_progress_time = {};
     }
 
     std::string TransferRate() {
@@ -153,6 +160,12 @@ struct TransferLedger {
 
     void ReportProgress(LinePrinter& lp, const std::string& file, uint64_t file_copied_bytes,
                         uint64_t file_total_bytes) {
+        static constexpr auto kProgressReportInterval = 100ms;
+
+        auto now = std::chrono::steady_clock::now();
+        if (now < last_progress_time + kProgressReportInterval) {
+            return;
+        }
         char overall_percentage_str[5] = "?";
         if (bytes_expected != 0 && bytes_transferred <= bytes_expected) {
             int overall_percentage = static_cast<int>(bytes_transferred * 100 / bytes_expected);
@@ -186,6 +199,7 @@ struct TransferLedger {
         if (output != last_progress_str) {
             lp.Print(output, LinePrinter::LineType::INFO);
             last_progress_str = std::move(output);
+            last_progress_time = now;
         }
     }