Implement common class for RamBuffer

core-buffer/include/RamBuffer.hpp

@@ -0,0 +1,32 @@
+#ifndef SF_DAQ_BUFFER_RAMBUFFER_HPP
+#define SF_DAQ_BUFFER_RAMBUFFER_HPP
+
+#include <string>
+#include "formats.hpp"
+
+class RamBuffer {
+    const std::string detector_name_;
+    const int module_n_;
+    const size_t n_slots_;
+    const size_t image_size_;
+    const size_t buffer_size_;
+
+    int shm_fd_;
+    void* buffer_;
+
+    ModuleFrame* meta_buffer_;
+    char* image_buffer_;
+
+
+public:
+    RamBuffer(const std::string& detector_name,
+              const size_t n_modules,
+              const int module_n,
+              const size_t n_slots);
+    ~RamBuffer();
+
+    void write_frame(const ModuleFrame& metadata, const char* data);
+};
+
+
+#endif //SF_DAQ_BUFFER_RAMBUFFER_HPP

core-buffer/include/RamBufferWriter.hpp

@@ -1,24 +0,0 @@
-#ifndef SF_DAQ_BUFFER_RAMBUFFERWRITER_HPP
-#define SF_DAQ_BUFFER_RAMBUFFERWRITER_HPP
-
-#include <string>
-
-class RamBufferWriter {
-    const int module_n_;
-    const std::string detector_name_;
-
-    int shm_fd_;
-    size_t buffer_size_;
-    void* buffer_;
-
-public:
-    RamBufferWriter(const std::string& detector_name,
-                    const int module_n,
-                    const size_t n_modules,
-                    const size_t n_slots);
-    ~RamBufferWriter();
-
-};
-
-
-#endif //SF_DAQ_BUFFER_RAMBUFFERWRITER_HPP

core-buffer/src/RamBuffer.cpp

@@ -0,0 +1,66 @@
+#include <sys/mman.h>
+#include <bits/fcntl-linux.h>
+#include <cstring>
+#include <stdexcept>
+#include <unistd.h>
+#include "RamBuffer.hpp"
+#include "buffer_config.hpp"
+
+using namespace std;
+using namespace buffer_config;
+
+RamBuffer::RamBuffer(
+        const string &detector_name,
+        const size_t n_modules,
+        const int module_n,
+        const size_t n_slots) :
+        detector_name_(detector_name),
+        module_n_(module_n),
+        n_slots_(n_slots),
+        image_size_(MODULE_N_BYTES * n_modules),
+        buffer_size_((sizeof(ModuleFrame) + image_size_) * n_slots)
+{
+    shm_fd_ = shm_open(detector_name_.c_str(), O_RDWR | O_CREAT, 0777);
+    if (shm_fd_ < 0) {
+        throw runtime_error(strerror(errno));
+    }
+
+    if ((ftruncate(shm_fd_, buffer_size_)) == -1) {
+        throw runtime_error(strerror(errno));
+    }
+
+    // TODO: Test with MAP_HUGETLB
+    buffer_ = mmap(NULL, buffer_size_, PROT_WRITE, MAP_SHARED, shm_fd_, 0);
+    if (buffer_ == MAP_FAILED) {
+        throw runtime_error(strerror(errno));
+    }
+
+    meta_buffer_ = (ModuleFrame *) buffer_;
+    // Image buffer start right after metadata buffer.
+    image_buffer_ = (char *) (meta_buffer_ + n_slots);
+}
+
+RamBuffer::~RamBuffer()
+{
+    munmap(buffer_, buffer_size_);
+    close(shm_fd_);
+    shm_unlink(detector_name_.c_str());
+
+}
+
+void RamBuffer::write_frame(
+        const ModuleFrame &metadata,
+        const char *data)
+{
+    size_t slot_n = metadata.pulse_id % n_slots_;
+
+    ModuleFrame *meta = meta_buffer_ + slot_n;
+    *meta = metadata;
+
+    char *frame = image_buffer_ +
+                  (image_size_ * slot_n) +
+                  (MODULE_N_BYTES * module_n_);
+
+    memcpy(frame, data, MODULE_N_BYTES);
+}
+

core-buffer/src/RamBufferWriter.cpp

@@ -1,48 +0,0 @@
-#include <sys/mman.h>
-#include <bits/fcntl-linux.h>
-#include <cstring>
-#include <stdexcept>
-#include <formats.hpp>
-#include <unistd.h>
-#include "RamBufferWriter.hpp"
-#include "buffer_config.hpp"
-
-using namespace std;
-using namespace buffer_config;
-
-RamBufferWriter::RamBufferWriter(
-        const string &detector_name,
-        const int module_n,
-        const size_t n_modules,
-        const size_t n_slots) :
-            detector_name_(detector_name),
-            module_n_(module_n)
-
-{
-    shm_fd_ = shm_open(detector_name_.c_str(), O_RDWR | O_CREAT, 0777);
-    if (shm_fd_ < 0) {
-        throw runtime_error(strerror(errno));
-    }
-
-    size_t slot_size = MODULE_N_BYTES + sizeof(ModuleFrame);
-    buffer_size_ = slot_size * n_modules * n_slots;
-
-    if ((ftruncate(shm_fd_, buffer_size_)) == -1) {
-        throw runtime_error(strerror(errno));
-    }
-
-    // TODO: Test with MAP_HUGETLB
-    void* ptr = mmap(NULL, buffer_size_, PROT_WRITE, MAP_SHARED, shm_fd_, 0);
-    if (ptr ==  MAP_FAILED) {
-        throw runtime_error(strerror(errno));
-    }
-
-    buffer_ = ptr;
-}
-
-RamBufferWriter::~RamBufferWriter()
-{
-    munmap(buffer_, buffer_size_);
-    shm_unlink(detector_name_.c_str());
-    close(shm_fd_);
-}