From 468ca4771ca34193971536deeff816d47a2d42a7 Mon Sep 17 00:00:00 2001
From: Wiebe Cazemier <wiebe@halfgaar.net>
Date: Sat, 27 Feb 2021 15:34:08 +0100
Subject: [PATCH] Refactor code to use new interface on CirBuf

---
 cirbuf.cpp     | 12 ++++++------
 cirbuf.h       |  3 ++-
 client.cpp     | 36 ++++--------------------------------
 mqttpacket.cpp | 13 +------------
 4 files changed, 13 insertions(+), 51 deletions(-)

diff --git a/cirbuf.cpp b/cirbuf.cpp
index 3ea3bce..0cf7593 100644
--- a/cirbuf.cpp
+++ b/cirbuf.cpp
@@ -90,20 +90,20 @@ char CirBuf::peakAhead(uint32_t offset) const
     return b;
 }
 
-void CirBuf::ensureFreeSpace(size_t n)
+void CirBuf::ensureFreeSpace(size_t n, const size_t max)
 {
+    if (n <= freeSpace())
+        return;
+
     const size_t _usedBytes = usedBytes();
 
     int mul = 1;
 
-    while((mul * size - _usedBytes - 1) < n)
+    while((mul * size - _usedBytes - 1) < n && (mul*size) < max)
     {
         mul = mul << 1;
     }
 
-    if (mul == 1)
-        return;
-
     doubleSize(mul);
 }
 
@@ -223,5 +223,5 @@ void CirBuf::read(void *buf, const size_t count)
         _packet_len -= readlen;
     }
     assert(_packet_len == 0);
-    assert(i == _packet_len);
+    assert(i == static_cast<int>(count));
 }
diff --git a/cirbuf.h b/cirbuf.h
index d2eca01..bd77060 100644
--- a/cirbuf.h
+++ b/cirbuf.h
@@ -4,6 +4,7 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdint.h>
+#include <limits.h>
 
 // Optimized circular buffer, works only with sizes power of two.
 class CirBuf
@@ -32,7 +33,7 @@ public:
     void advanceHead(uint32_t n);
     void advanceTail(uint32_t n);
     char peakAhead(uint32_t offset) const;
-    void ensureFreeSpace(size_t n);
+    void ensureFreeSpace(size_t n, const size_t max = UINT_MAX);
     void doubleSize(uint factor = 2);
     uint32_t getSize() const;
 
diff --git a/client.cpp b/client.cpp
index a7ed216..e7fb8d9 100644
--- a/client.cpp
+++ b/client.cpp
@@ -147,10 +147,7 @@ void Client::writeMqttPacket(const MqttPacket &packet)
     const uint32_t growBufMaxTo = std::min<int>(packet.getSizeIncludingNonPresentHeader() * 1000, maxPacketSize);
 
     // Grow as far as we can. We have to make room for one MQTT packet.
-    while (packet.getSizeIncludingNonPresentHeader() > writebuf.freeSpace() && writebuf.getSize() < growBufMaxTo)
-    {
-        writebuf.doubleSize();
-    }
+    writebuf.ensureFreeSpace(packet.getSizeIncludingNonPresentHeader(), growBufMaxTo);
 
     // And drop a publish when it doesn't fit, even after resizing. This means we do allow pings. And
     // QoS packet are queued and limited elsewhere.
@@ -164,34 +161,10 @@ void Client::writeMqttPacket(const MqttPacket &packet)
         writebuf.headPtr()[0] = packet.getFirstByte();
         writebuf.advanceHead(1);
         RemainingLength r = packet.getRemainingLength();
-
-        ssize_t len_left = r.len;
-        int src_i = 0;
-        while (len_left > 0)
-        {
-            const size_t len = std::min<int>(len_left, writebuf.maxWriteSize());
-            assert(len > 0);
-            std::memcpy(writebuf.headPtr(), &r.bytes[src_i], len);
-            writebuf.advanceHead(len);
-            src_i += len;
-            len_left -= len;
-        }
-        assert(len_left == 0);
-        assert(src_i == r.len);
+        writebuf.write(r.bytes, r.len);
     }
 
-    ssize_t len_left = packet.getBites().size();
-    int src_i = 0;
-    while (len_left > 0)
-    {
-        const size_t len = std::min<int>(len_left, writebuf.maxWriteSize());
-        assert(len > 0);
-        std::memcpy(writebuf.headPtr(), &packet.getBites()[src_i], len);
-        writebuf.advanceHead(len);
-        src_i += len;
-        len_left -= len;
-    }
-    assert(len_left == 0);
+    writebuf.write(packet.getBites().data(), packet.getBites().size());
 
     if (packet.packetType == PacketType::DISCONNECT)
         setReadyForDisconnect();
@@ -217,8 +190,7 @@ void Client::writePingResp()
 {
     std::lock_guard<std::mutex> locker(writeBufMutex);
 
-    if (2 > writebuf.freeSpace())
-        writebuf.doubleSize();
+    writebuf.ensureFreeSpace(2);
 
     writebuf.headPtr()[0] = 0b11010000;
     writebuf.advanceHead(1);
diff --git a/mqttpacket.cpp b/mqttpacket.cpp
index bf1e5f3..2b940ee 100644
--- a/mqttpacket.cpp
+++ b/mqttpacket.cpp
@@ -17,18 +17,7 @@ MqttPacket::MqttPacket(CirBuf &buf, size_t packet_len, size_t fixed_header_lengt
     fixed_header_length(fixed_header_length),
     sender(sender)
 {
-    int i = 0;
-    ssize_t _packet_len = packet_len;
-    while (_packet_len > 0)
-    {
-        int readlen = std::min<int>(buf.maxReadSize(), _packet_len);
-        assert(readlen > 0);
-        std::memcpy(&bites[i], buf.tailPtr(), readlen);
-        buf.advanceTail(readlen);
-        i += readlen;
-        _packet_len -= readlen;
-    }
-    assert(_packet_len == 0);
+    buf.read(bites.data(), packet_len);
 
     first_byte = bites[0];
     unsigned char _packetType = (first_byte & 0xF0) >> 4;
--
libgit2 0.21.4