From 6823d2d8cd304007fd688f66bc2dcacdb2c9777a Mon Sep 17 00:00:00 2001
From: Changcheng Liu <changcheng.liu@aliyun.com>
Date: Wed, 26 Jun 2019 14:31:29 +0800
Subject: [PATCH] msg/async/rdma: avoid long lambda function for readability

Extract the long lambda function to improve readability.
There's no advantage since "this" pointer is also needed
in original lambad function.

Signed-off-by: Changcheng Liu <changcheng.liu@aliyun.com>
---
 src/msg/async/rdma/RDMAConnectedSocketImpl.cc | 81 ++++++++++---------
 src/msg/async/rdma/RDMAStack.h                |  3 +
 2 files changed, 45 insertions(+), 39 deletions(-)

diff --git a/src/msg/async/rdma/RDMAConnectedSocketImpl.cc b/src/msg/async/rdma/RDMAConnectedSocketImpl.cc
index 327eaaa0b89..8f63fecb905 100644
--- a/src/msg/async/rdma/RDMAConnectedSocketImpl.cc
+++ b/src/msg/async/rdma/RDMAConnectedSocketImpl.cc
@@ -436,6 +436,44 @@ ssize_t RDMAConnectedSocketImpl::send(bufferlist &bl, bool more)
   return bytes;
 }
 
+size_t RDMAConnectedSocketImpl::tx_copy_chunk(std::vector<Chunk*> &tx_buffers,
+    size_t req_copy_len, decltype(std::cbegin(pending_bl.buffers()))& start,
+    const decltype(std::cbegin(pending_bl.buffers()))& end)
+{
+  ceph_assert(start != end);
+  auto chunk_idx = tx_buffers.size();
+  if (0 == worker->get_reged_mem(this, tx_buffers, req_copy_len)) {
+    ldout(cct, 1) << __func__ << " no enough buffers in worker " << worker << dendl;
+    worker->perf_logger->inc(l_msgr_rdma_tx_no_mem);
+    return 0;
+  }
+
+  Chunk *current_chunk = tx_buffers[chunk_idx];
+  size_t write_len = 0;
+  while (start != end) {
+    const uintptr_t addr = reinterpret_cast<uintptr_t>(start->c_str());
+
+    size_t slice_write_len = 0;
+    while (slice_write_len < start->length()) {
+      size_t real_len = current_chunk->write((char*)addr + slice_write_len, start->length() - slice_write_len);
+
+      slice_write_len += real_len;
+      write_len += real_len;
+      req_copy_len -= real_len;
+
+      if (current_chunk->full()) {
+        if (++chunk_idx == tx_buffers.size())
+          return write_len;
+        current_chunk = tx_buffers[chunk_idx];
+      }
+    }
+
+    ++start;
+  }
+  ceph_assert(req_copy_len == 0);
+  return write_len;
+}
+
 ssize_t RDMAConnectedSocketImpl::submit(bool more)
 {
   if (error)
@@ -447,50 +485,15 @@ ssize_t RDMAConnectedSocketImpl::submit(bool more)
   if (!bytes)
     return 0;
 
-  auto fill_tx_via_copy = [this](std::vector<Chunk*> &tx_buffers,
-                                 unsigned bytes,
-                                 auto& start,
-                                 const auto& end) -> unsigned {
-    ceph_assert(start != end);
-    auto chunk_idx = tx_buffers.size();
-    int ret = worker->get_reged_mem(this, tx_buffers, bytes);
-    if (ret == 0) {
-      ldout(cct, 1) << __func__ << " no enough buffers in worker " << worker << dendl;
-      worker->perf_logger->inc(l_msgr_rdma_tx_no_mem);
-      return 0;
-    }
-
-    unsigned total_copied = 0;
-    Chunk *current_chunk = tx_buffers[chunk_idx];
-    while (start != end) {
-      const uintptr_t addr = reinterpret_cast<uintptr_t>(start->c_str());
-      unsigned copied = 0;
-      while (copied < start->length()) {
-        uint32_t r = current_chunk->write((char*)addr+copied, start->length() - copied);
-        copied += r;
-        total_copied += r;
-        bytes -= r;
-        if (current_chunk->full()){
-          if (++chunk_idx == tx_buffers.size())
-            return total_copied;
-          current_chunk = tx_buffers[chunk_idx];
-        }
-      }
-      ++start;
-    }
-    ceph_assert(bytes == 0);
-    return total_copied;
-  };
-
   std::vector<Chunk*> tx_buffers;
   auto it = std::cbegin(pending_bl.buffers());
   auto copy_it = it;
-  unsigned total = 0;
-  unsigned need_reserve_bytes = 0;
+  size_t total = 0;
+  size_t need_reserve_bytes = 0;
   while (it != pending_bl.buffers().end()) {
     if (infiniband->is_tx_buffer(it->raw_c_str())) {
       if (need_reserve_bytes) {
-        unsigned copied = fill_tx_via_copy(tx_buffers, need_reserve_bytes, copy_it, it);
+        size_t copied = tx_copy_chunk(tx_buffers, need_reserve_bytes, copy_it, it);
         total += copied;
         if (copied < need_reserve_bytes)
           goto sending;
@@ -506,7 +509,7 @@ ssize_t RDMAConnectedSocketImpl::submit(bool more)
     ++it;
   }
   if (need_reserve_bytes)
-    total += fill_tx_via_copy(tx_buffers, need_reserve_bytes, copy_it, it);
+    total += tx_copy_chunk(tx_buffers, need_reserve_bytes, copy_it, it);
 
  sending:
   if (total == 0)
diff --git a/src/msg/async/rdma/RDMAStack.h b/src/msg/async/rdma/RDMAStack.h
index 8033a5b91fe..7a83260a540 100644
--- a/src/msg/async/rdma/RDMAStack.h
+++ b/src/msg/async/rdma/RDMAStack.h
@@ -209,6 +209,9 @@ class RDMAConnectedSocketImpl : public ConnectedSocketImpl {
   void notify();
   ssize_t read_buffers(char* buf, size_t len);
   int post_work_request(std::vector<Chunk*>&);
+  size_t tx_copy_chunk(std::vector<Chunk*> &tx_buffers, size_t req_copy_len,
+      decltype(std::cbegin(pending_bl.buffers()))& start,
+      const decltype(std::cbegin(pending_bl.buffers()))& end);
 
  public:
   RDMAConnectedSocketImpl(CephContext *cct, Infiniband* ib, RDMADispatcher* s,
-- 
2.39.5