client: add SimpleStreamBuffer

client/CMakeLists.txt

@@ -14,6 +14,7 @@ add_executable(badvpn-client
     DataProtoKeepaliveSource.c
     PeerChat.c
     SCOutmsgEncoder.c
+    SimpleStreamBuffer.c
     SinglePacketSource.c
 )
 target_link_libraries(badvpn-client system flow flowextra tuntap server_conection security ${NSPR_LIBRARIES} ${NSS_LIBRARIES})

client/SimpleStreamBuffer.c

@@ -0,0 +1,137 @@
+/**
+ * @file SimpleStreamBuffer.c
+ * @author Ambroz Bizjak <ambrop7@gmail.com>
+ * 
+ * @section LICENSE
+ * 
+ * This file is part of BadVPN.
+ * 
+ * BadVPN is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ * 
+ * BadVPN is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <string.h>
+#include <stddef.h>
+
+#include <misc/balloc.h>
+#include <misc/minmax.h>
+
+#include "SimpleStreamBuffer.h"
+
+static void try_output (SimpleStreamBuffer *o)
+{
+    ASSERT(o->output_data_len > 0)
+    
+    // calculate number of bytes to output
+    int bytes = bmin_int(o->output_data_len, o->buf_used);
+    if (bytes == 0) {
+        return;
+    }
+    
+    // copy bytes to output
+    memcpy(o->output_data, o->buf, bytes);
+    
+    // shift buffer
+    memmove(o->buf, o->buf + bytes, o->buf_used - bytes);
+    o->buf_used -= bytes;
+    
+    // forget data
+    o->output_data_len = -1;
+    
+    // done
+    StreamRecvInterface_Done(&o->output, bytes);
+}
+
+static void output_handler_recv (SimpleStreamBuffer *o, uint8_t *data, int data_len)
+{
+    DebugObject_Access(&o->d_obj);
+    ASSERT(o->output_data_len == -1)
+    ASSERT(data)
+    ASSERT(data_len > 0)
+    
+    // remember data
+    o->output_data = data;
+    o->output_data_len = data_len;
+    
+    try_output(o);
+}
+
+int SimpleStreamBuffer_Init (SimpleStreamBuffer *o, int buf_size, BPendingGroup *pg)
+{
+    ASSERT(buf_size > 0)
+    
+    // init arguments
+    o->buf_size = buf_size;
+    
+    // init output
+    StreamRecvInterface_Init(&o->output, (StreamRecvInterface_handler_recv)output_handler_recv, o, pg);
+    
+    // allocate buffer
+    if (!(o->buf = BAlloc(buf_size))) {
+        goto fail1;
+    }
+    
+    // init buffer state
+    o->buf_used = 0;
+    
+    // set no output data
+    o->output_data_len = -1;
+    
+    DebugObject_Init(&o->d_obj);
+    return 1;
+    
+fail1:
+    StreamRecvInterface_Free(&o->output);
+    return 0;
+}
+
+void SimpleStreamBuffer_Free (SimpleStreamBuffer *o)
+{
+    DebugObject_Free(&o->d_obj);
+    
+    // free buffer
+    BFree(o->buf);
+    
+    // free output
+    StreamRecvInterface_Free(&o->output);
+}
+
+StreamRecvInterface * SimpleStreamBuffer_GetOutput (SimpleStreamBuffer *o)
+{
+    DebugObject_Access(&o->d_obj);
+    
+    return &o->output;
+}
+
+int SimpleStreamBuffer_Write (SimpleStreamBuffer *o, uint8_t *data, int data_len)
+{
+    DebugObject_Access(&o->d_obj);
+    ASSERT(data_len >= 0)
+    
+    if (data_len > o->buf_size - o->buf_used) {
+        return 0;
+    }
+    
+    // copy to buffer
+    memcpy(o->buf + o->buf_used, data, data_len);
+    
+    // update buffer state
+    o->buf_used += data_len;
+    
+    // continue outputting
+    if (o->output_data_len > 0) {
+        try_output(o);
+    }
+    
+    return 1;
+}

client/SimpleStreamBuffer.h

@@ -0,0 +1,45 @@
+/**
+ * @file SimpleStreamBuffer.h
+ * @author Ambroz Bizjak <ambrop7@gmail.com>
+ * 
+ * @section LICENSE
+ * 
+ * This file is part of BadVPN.
+ * 
+ * BadVPN is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ * 
+ * BadVPN is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef BADVPN_SIMPLESTREAMBUFFER_H
+#define BADVPN_SIMPLESTREAMBUFFER_H
+
+#include <misc/debug.h>
+#include <base/DebugObject.h>
+#include <flow/StreamRecvInterface.h>
+
+typedef struct {
+    int buf_size;
+    StreamRecvInterface output;
+    uint8_t *buf;
+    int buf_used;
+    uint8_t *output_data;
+    int output_data_len;
+    DebugObject d_obj;
+} SimpleStreamBuffer;
+
+int SimpleStreamBuffer_Init (SimpleStreamBuffer *o, int buf_size, BPendingGroup *pg) WARN_UNUSED;
+void SimpleStreamBuffer_Free (SimpleStreamBuffer *o);
+StreamRecvInterface * SimpleStreamBuffer_GetOutput (SimpleStreamBuffer *o);
+int SimpleStreamBuffer_Write (SimpleStreamBuffer *o, uint8_t *data, int data_len) WARN_UNUSED;
+
+#endif