From 91972ad2cb62131476752ab988c53f1fa9864d15 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Tue, 26 May 2009 09:39:30 -0700
Subject: [PATCH] librados: remove length args from C++ interface

The bufferlists remove any need for an additional length arg.

Return ERANGE when buffers are too small.
---
 src/include/librados.h |  2 +-
 src/librados.cc        | 36 +++++++++++++++++++++---------------
 src/testradospp.cc     |  2 +-
 3 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/src/include/librados.h b/src/include/librados.h
index 0291e1b1d6abf..7241cd8ef946e 100644
--- a/src/include/librados.h
+++ b/src/include/librados.h
@@ -53,7 +53,7 @@ public:
   int remove(rados_pool_t pool, object_t& oid);
 
   int exec(rados_pool_t pool, object_t& oid, const char *cls, const char *method,
-             bufferlist& inbl, size_t in_len, bufferlist& outbl, size_t out_len);
+             bufferlist& inbl, bufferlist& outbl);
 };
 #endif
 
diff --git a/src/librados.cc b/src/librados.cc
index f47b5be79607c..78f9d17bc9528 100644
--- a/src/librados.cc
+++ b/src/librados.cc
@@ -72,7 +72,7 @@ public:
   int read(int pool, object_t& oid, off_t off, bufferlist& bl, size_t len);
   int remove(int pool, object_t& oid);
 
-  int exec(int pool, object_t& oid, const char *cls, const char *method, bufferlist& inbl, size_t in_len, bufferlist& outbl, size_t out_len);
+  int exec(int pool, object_t& oid, const char *cls, const char *method, bufferlist& inbl, bufferlist& outbl);
 };
 
 bool RadosClient::init()
@@ -234,7 +234,8 @@ int RadosClient::remove(int pool, object_t& oid)
   return r;
 }
 
-int RadosClient::exec(int pool, object_t& oid, const char *cls, const char *method, bufferlist& inbl, size_t in_len, bufferlist& outbl, size_t out_len)
+int RadosClient::exec(int pool, object_t& oid, const char *cls, const char *method,
+		      bufferlist& inbl, bufferlist& outbl)
 {
   SnapContext snapc;
   utime_t ut = g_clock.now();
@@ -250,7 +251,6 @@ int RadosClient::exec(int pool, object_t& oid, const char *cls, const char *meth
   lock.Lock();
 
   ObjectRead rd;
-
   rd.rdcall(cls, method, inbl);
   objecter->read(oid, layout, rd, CEPH_NOSNAP, &outbl, 0, onack);
 
@@ -261,10 +261,7 @@ int RadosClient::exec(int pool, object_t& oid, const char *cls, const char *meth
 
   lock.Unlock();
 
-  if (outbl.length() < out_len)
-    out_len = outbl.length();
-
-  return out_len;
+  return r;
 }
 
 int RadosClient::read(int pool, object_t& oid, off_t off, bufferlist& bl, size_t len)
@@ -348,12 +345,12 @@ int Rados::read(rados_pool_t pool, object_t& oid, off_t off, bufferlist& bl, siz
 }
 
 int Rados::exec(rados_pool_t pool, object_t& oid, const char *cls, const char *method,
-             bufferlist& inbl, size_t in_len, bufferlist& outbl, size_t out_len)
+		bufferlist& inbl, bufferlist& outbl)
 {
   if (!client)
     return -EINVAL;
 
-  return client->exec(pool, oid, cls, method, inbl, in_len, outbl, out_len);
+  return client->exec(pool, oid, cls, method, inbl, outbl);
 }
 
 int Rados::open_pool(const char *name, rados_pool_t *pool)
@@ -464,8 +461,12 @@ extern "C" int rados_read(rados_pool_t pool, ceph_object *o, off_t off, char *bu
   object_t oid(*o);
   bufferlist bl;
   ret = radosp->read(pool, oid, off, bl, len);
-  if (ret > 0)
-    memcpy(buf, bl.c_str(), ret);
+  if (ret >= 0) {
+    if (bl.length() > len)
+      return -ERANGE;
+    bl.copy(0, bl.length(), buf);
+    ret = bl.length();    // hrm :/
+  }
 
   return ret;
 }
@@ -477,10 +478,15 @@ extern "C" int rados_exec(rados_pool_t pool, ceph_object *o, const char *cls, co
   bufferlist inbl, outbl;
   int ret;
   inbl.append(inbuf, in_len);
-  ret = radosp->exec(pool, oid, cls, method, inbl, in_len, outbl, out_len);
-  if (ret > 0)
-    memcpy(buf, outbl.c_str(), ret);
-
+  ret = radosp->exec(pool, oid, cls, method, inbl, outbl);
+  if (ret >= 0) {
+    if (outbl.length()) {
+      if (outbl.length() > out_len)
+	return -ERANGE;
+      outbl.copy(0, outbl.length(), buf);
+      ret = outbl.length();   // hrm :/
+    }
+  }
   return ret;
 }
 
diff --git a/src/testradospp.cc b/src/testradospp.cc
index 7f66a4d6e78f4..8cd68c55d3973 100644
--- a/src/testradospp.cc
+++ b/src/testradospp.cc
@@ -44,7 +44,7 @@ int main(int argc, const char **argv)
   cout << "open pool result = " << r << " pool = " << pool << std::endl;
 
   rados.write(pool, oid, 0, bl, bl.length());
-  rados.exec(pool, oid, "test", "foo", bl, bl.length(), bl2, 1024);
+  rados.exec(pool, oid, "test", "foo", bl, bl2);
   cout << "exec result=" << bl2.c_str() << std::endl;
   int size = rados.read(pool, oid, 0, bl2, 128);
 
-- 
2.39.5