Golang bindings initial working version(#534)

* WIP

* Fix includes

* Try to fix linking issues

* Refinements

* allow to load MPT and llama models too

* cleanup, add example, add README

gpt4all-bindings/golang/binding.cpp

@@ -0,0 +1,127 @@
+#include "../../gpt4all-backend/llmodel_c.h"
+#include "../../gpt4all-backend/llmodel.h"
+#include "../../gpt4all-backend/llama.cpp/llama.h"
+#include "../../gpt4all-backend/llmodel_c.cpp"
+#include "../../gpt4all-backend/mpt.h"
+#include "../../gpt4all-backend/mpt.cpp"
+
+#include "../../gpt4all-backend/llamamodel.h"
+#include "../../gpt4all-backend/gptj.h"
+#include "binding.h"
+#include <cassert>
+#include <cmath>
+#include <cstdio>
+#include <cstring>
+#include <fstream>
+#include <map>
+#include <string>
+#include <vector>
+#include <iostream>
+#include <unistd.h>
+
+void* load_mpt_model(const char *fname, int n_threads) {
+    // load the model
+    auto gptj = llmodel_mpt_create();
+
+    llmodel_setThreadCount(gptj,  n_threads);
+    if (!llmodel_loadModel(gptj, fname)) {
+        return nullptr;
+    }
+
+    return gptj;
+}
+
+void* load_llama_model(const char *fname, int n_threads) {
+    // load the model
+    auto gptj = llmodel_llama_create();
+
+    llmodel_setThreadCount(gptj,  n_threads);
+    if (!llmodel_loadModel(gptj, fname)) {
+        return nullptr;
+    }
+
+    return gptj;
+}
+
+void* load_gptj_model(const char *fname, int n_threads) {
+    // load the model
+    auto gptj = llmodel_gptj_create();
+
+    llmodel_setThreadCount(gptj,  n_threads);
+    if (!llmodel_loadModel(gptj, fname)) {
+        return nullptr;
+    }
+
+    return gptj;
+}
+
+std::string res = "";
+void * mm;
+
+void gptj_model_prompt( const char *prompt, void *m, char* result, int repeat_last_n, float repeat_penalty, int n_ctx, int tokens, int top_k,
+                            float top_p, float temp, int n_batch,float ctx_erase)
+{
+    llmodel_model* model = (llmodel_model*) m;
+
+   // std::string res = "";
+ 
+    auto lambda_prompt = [](int token_id, const char *promptchars)  {
+	        return true;
+    };
+
+    mm=model;
+    res="";
+
+    auto lambda_response = [](int token_id, const char *responsechars) {
+        res.append((char*)responsechars);
+        return !!getTokenCallback(mm, (char*)responsechars);
+	};
+	
+	auto lambda_recalculate = [](bool is_recalculating) {
+	        // You can handle recalculation requests here if needed
+	    return is_recalculating;
+	};
+
+    llmodel_prompt_context* prompt_context = new llmodel_prompt_context{
+        .logits = NULL,
+        .logits_size = 0,
+        .tokens = NULL,
+        .tokens_size = 0,
+        .n_past = 0,
+        .n_ctx = 1024,
+        .n_predict = 50,
+        .top_k = 10,
+        .top_p = 0.9,
+        .temp = 1.0,
+        .n_batch = 1,
+        .repeat_penalty = 1.2,
+        .repeat_last_n = 10,
+        .context_erase = 0.5
+    };
+
+    prompt_context->n_predict = tokens;
+    prompt_context->repeat_last_n = repeat_last_n;
+    prompt_context->repeat_penalty = repeat_penalty;
+    prompt_context->n_ctx = n_ctx;
+    prompt_context->top_k = top_k;
+    prompt_context->context_erase = ctx_erase;
+    prompt_context->top_p = top_p;
+    prompt_context->temp = temp;
+    prompt_context->n_batch = n_batch;    
+
+    llmodel_prompt(model, prompt,
+                        lambda_prompt,
+                        lambda_response,
+                    lambda_recalculate,
+                    prompt_context );
+
+    strcpy(result, res.c_str()); 
+
+    free(prompt_context);
+}
+
+void gptj_free_model(void *state_ptr) {
+    llmodel_model* ctx = (llmodel_model*) state_ptr;
+    llmodel_llama_destroy(ctx);
+}
+