From 34fd921b89577cee691ba5e69bed6c06554bd736 Mon Sep 17 00:00:00 2001
From: Prem Chaitanya Prathi <chaitanyaprem@gmail.com>
Date: Thu, 22 Feb 2024 15:19:27 +0530
Subject: [PATCH] chore: experimenting with callback

---
 cpp/negentropy.h         |  3 ++-
 cpp/negentropy_wrapper.c | 24 ++++++++++++++----------
 cpp/negentropy_wrapper.h |  7 +++----
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/cpp/negentropy.h b/cpp/negentropy.h
index d3de53e..9a8e4ee 100644
--- a/cpp/negentropy.h
+++ b/cpp/negentropy.h
@@ -14,6 +14,7 @@
 #include <stdexcept>
 #include <optional>
 #include <bit>
+#include <iostream>
 
 #include "negentropy/encoding.h"
 #include "negentropy/types.h"
@@ -49,7 +50,7 @@ struct Negentropy {
 
         std::string output;
         output.push_back(PROTOCOL_VERSION);
-
+        std::cout << "storage size" << storage.size() << std::endl;
         output += splitRange(0, storage.size(), Bound(MAX_U64));
 
         return output;
diff --git a/cpp/negentropy_wrapper.c b/cpp/negentropy_wrapper.c
index 0499d63..501e86d 100644
--- a/cpp/negentropy_wrapper.c
+++ b/cpp/negentropy_wrapper.c
@@ -7,8 +7,6 @@
 //This is a C-wrapper for the C++ library that helps in integrating negentropy with nim code.
 //TODO: Do error handling by catching exceptions
 
-using namespace std;
-
 void* storage_new(const char* db_path, const char* name){
     negentropy::storage::BTreeMem* storage;
 /* 
@@ -44,18 +42,23 @@ void* negentropy_new(void* storage, uint64_t frameSizeLimit){
     return ne;
 }
 
-const char* negentropy_initiate(void* negentropy){
+void negentropy_initiate(void* negentropy, void (*callback)(const char* buf, size_t len)){
     Negentropy<negentropy::storage::BTreeMem>* ngn_inst;
     ngn_inst = reinterpret_cast<Negentropy<negentropy::storage::BTreeMem>*>(negentropy);
 
-    std::string* output = new std::string();
+    std::string output;
     try {
-        *output = ngn_inst->initiate();
+        output = ngn_inst->initiate();
+        std::cout << "output of initiate is, len:" << output.size() << std::hex << output << std::endl;
     } catch(negentropy::err e){
         //TODO:Find a way to return this error
-        return NULL;
+        callback(NULL,0);
+        return ;
     }
-    return output->c_str();
+    callback(output.c_str(), output.size());
+    //TODO: Avoid copy and use a callback
+    //memcpy(buf, output, output.size())
+    return ;
 }
 
 void negentropy_setinitiator(void* negentropy){
@@ -70,7 +73,7 @@ void negentropy_setinitiator(void* negentropy){
 bool storage_insert(void* storage, uint64_t createdAt, buffer* id){
     negentropy::storage::BTreeMem* lmdbStorage;
     lmdbStorage = reinterpret_cast<negentropy::storage::BTreeMem*>(storage);
-    std::cout << "inserting entry in storage, createdAt:" << createdAt << ",id:" << std::string_view(id->data, id->len) << "length is:"<< id->len << std::endl;
+    std::cout << "inserting entry in storage, createdAt:" << createdAt << ",id:" << std::hex << id->data << " length is:"<< id->len << std::endl;
     //TODO: Error handling. Is it required?
     //How does out of memory get handled?
     return lmdbStorage->insert(createdAt, std::string_view(id->data, id->len));
@@ -122,6 +125,7 @@ const char* reconcile_with_ids(void* negentropy, buffer*  query, char* have_ids[
         *have_ids_len = haveIds.size();
         *need_ids_len = needIds.size();
         //TODO: Optimize to not copy and rather return memory reference.
+        std::cout << "*have_ids_len:" << *have_ids_len << "*need_ids_len:" << *need_ids_len << "output has value" << output->has_value() << std::endl;
 
         std::transform(haveIds.begin(), haveIds.end(), have_ids, convert);
         std::transform(needIds.begin(), needIds.end(), need_ids, convert);
@@ -130,11 +134,11 @@ const char* reconcile_with_ids(void* negentropy, buffer*  query, char* have_ids[
         //TODO:Find a way to return this error
         return NULL;
     }
-    if (output->has_value()) {
+    if (!output->has_value()) {
         //TODO: Figure out diff between error and this.
         return NULL;
     }else {
-        
+        std::cout << "output value" << output->value() << std::endl;
         return output->value().c_str();
     }
 }
diff --git a/cpp/negentropy_wrapper.h b/cpp/negentropy_wrapper.h
index bc979aa..0416b54 100644
--- a/cpp/negentropy_wrapper.h
+++ b/cpp/negentropy_wrapper.h
@@ -1,4 +1,3 @@
-
 #ifndef _NEGENTROPY_WRAPPER_H
 #define _NEGENTROPY_WRAPPER_H
 
@@ -20,7 +19,7 @@ EXTERNC void* storage_new(const char* db_path, const char* name);
 
 EXTERNC void* negentropy_new(void* storage, uint64_t frameSizeLimit);
 
-EXTERNC const char* negentropy_initiate(void* negentropy);
+EXTERNC void negentropy_initiate(void* negentropy, void *(const char* buf, size_t len));
 
 EXTERNC void negentropy_setinitiator(void* negentropy);
 
@@ -30,8 +29,8 @@ EXTERNC bool storage_erase(void* storage, uint64_t createdAt, buffer* id);
 
 EXTERNC const char* reconcile(void* negentropy, buffer* query);
 
-EXTERNC const char* reconcile_with_ids(void* negentropy, buffer*  query, const char* have_ids[], 
-                                        uint64_t *have_ids_len, const char* need_ids[], uint64_t *need_ids_len);
+EXTERNC const char* reconcile_with_ids(void* negentropy, buffer*  query, char* have_ids[], 
+                                        uint64_t *have_ids_len, char* need_ids[], uint64_t *need_ids_len);
 
 #endif