From de2a32be7bb4422748adfa28e4531d2c0905c16d Mon Sep 17 00:00:00 2001
From: Davin McCall <davmac@davmac.org>
Date: Sat, 16 Jan 2016 12:54:05 +0000
Subject: [PATCH] Make CPBuffer a template, parameterized by buffer size

---
 src/control.h   |  2 +-
 src/cpbuffer.h  | 26 +++++++++++++-------------
 src/dinitctl.cc |  8 ++++----
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/control.h b/src/control.h
index f027f01..9f10fed 100644
--- a/src/control.h
+++ b/src/control.h
@@ -60,7 +60,7 @@ class ControlConn : private ServiceListener
     int chklen;
     
     // Receive buffer
-    CPBuffer rbuf;
+    CPBuffer<1024> rbuf;
     
     template <typename T> using list = std::list<T>;
     template <typename T> using vector = std::vector<T>;
diff --git a/src/cpbuffer.h b/src/cpbuffer.h
index 94132ca..751cbf8 100644
--- a/src/cpbuffer.h
+++ b/src/cpbuffer.h
@@ -4,9 +4,9 @@
 #include <cstring>
 
 // control protocol buffer, a circular buffer with 1024-byte capacity.
-class CPBuffer
+template <int SIZE> class CPBuffer
 {
-    char buf[1024];
+    char buf[SIZE];
     int cur_idx = 0;
     int length = 0;  // number of elements in the buffer
     
@@ -20,8 +20,8 @@ class CPBuffer
     int fill(int fd) noexcept
     {
         int pos = cur_idx + length;
-        if (pos >= 1024) pos -= 1024;
-        int max_count = std::min(1024 - pos, 1024 - length);
+        if (pos >= SIZE) pos -= SIZE;
+        int max_count = std::min(SIZE - pos, SIZE - length);
         ssize_t r = read(fd, buf + pos, max_count);
         if (r >= 0) {
             length += r;
@@ -43,24 +43,24 @@ class CPBuffer
     int operator[](int idx) noexcept
     {
         int dest_idx = cur_idx + idx;
-        if (dest_idx > 1024) dest_idx -= 1024;
+        if (dest_idx > SIZE) dest_idx -= SIZE;
         return buf[dest_idx];
     }
     
     void consume(int amount) noexcept
     {
         cur_idx += amount;
-        if (cur_idx >= 1024) cur_idx -= 1024;
+        if (cur_idx >= SIZE) cur_idx -= SIZE;
         length -= amount;
     }
     
     void extract(char *dest, int index, int length) noexcept
     {
         index += cur_idx;
-        if (index >= 1024) index -= 1024;
-        if (index + length > 1024) {
+        if (index >= SIZE) index -= SIZE;
+        if (index + length > SIZE) {
             // wrap-around copy
-            int half = 1024 - index;
+            int half = SIZE - index;
             std::memcpy(dest, buf + index, half);
             std::memcpy(dest + half, buf, length - half);
         }
@@ -74,10 +74,10 @@ class CPBuffer
     std::string extract_string(int index, int length)
     {
         index += cur_idx;
-        if (index >= 1024) index -= 1024;
-        if (index + length > 1024) {
-            std::string r(buf + index, 1024 - index);
-            r.insert(r.end(), buf, buf + length - (1024 - index));
+        if (index >= SIZE) index -= SIZE;
+        if (index + length > SIZE) {
+            std::string r(buf + index, SIZE - index);
+            r.insert(r.end(), buf, buf + length - (SIZE - index));
             return r;
         }
         else {
diff --git a/src/dinitctl.cc b/src/dinitctl.cc
index 0928bb8..1e5c2fe 100644
--- a/src/dinitctl.cc
+++ b/src/dinitctl.cc
@@ -30,7 +30,7 @@ class ReadCPException
     ReadCPException(int err) : errcode(err) { }
 };
 
-static void fillBufferTo(CPBuffer *buf, int fd, int rlength)
+static void fillBufferTo(CPBuffer<1024> *buf, int fd, int rlength)
 {
     int r = buf->fillTo(fd, rlength);
     if (r == -1) {
@@ -53,7 +53,7 @@ static const char * describeVerb(bool stop)
 
 // Wait for a reply packet, skipping over any information packets
 // that are received in the meantime.
-static void wait_for_reply(CPBuffer &rbuffer, int fd)
+static void wait_for_reply(CPBuffer<1024> &rbuffer, int fd)
 {
     fillBufferTo(&rbuffer, fd, 1);
     
@@ -263,7 +263,7 @@ int main(int argc, char **argv)
     // Now we expect a reply:
     
     try {
-        CPBuffer rbuffer;
+        CPBuffer<1024> rbuffer;
         wait_for_reply(rbuffer, socknum);
         
         //ServiceState state;
@@ -443,7 +443,7 @@ static int unpinService(int socknum, const char *service_name)
     // Now we expect a reply:
     
     try {
-        CPBuffer rbuffer;
+        CPBuffer<1024> rbuffer;
         wait_for_reply(rbuffer, socknum);
         
         //ServiceState state;
-- 
2.25.1