Move the llmodel C API to new top-level directory and version it.

gpt4all-backend/llmodel.h

@@ -0,0 +1,47 @@
+#ifndef LLMODEL_H
+#define LLMODEL_H
+
+#include <string>
+#include <functional>
+#include <vector>
+#include <cstdint>
+
+class LLModel {
+public:
+    explicit LLModel() {}
+    virtual ~LLModel() {}
+
+    virtual bool loadModel(const std::string &modelPath) = 0;
+    virtual bool isModelLoaded() const = 0;
+    virtual size_t stateSize() const { return 0; }
+    virtual size_t saveState(uint8_t *dest) const { return 0; }
+    virtual size_t restoreState(const uint8_t *src) { return 0; }
+    struct PromptContext {
+        std::vector<float> logits;      // logits of current context
+        std::vector<int32_t> tokens;    // current tokens in the context window
+        int32_t n_past = 0;             // number of tokens in past conversation
+        int32_t n_ctx = 0;              // number of tokens possible in context window
+        int32_t n_predict = 200;
+        int32_t top_k = 40;
+        float   top_p = 0.9f;
+        float   temp = 0.9f;
+        int32_t n_batch = 9;
+        float   repeat_penalty = 1.10f;
+        int32_t repeat_last_n = 64;     // last n tokens to penalize
+        float   contextErase = 0.75f;   // percent of context to erase if we exceed the context
+                                        // window
+    };
+    virtual void prompt(const std::string &prompt,
+        std::function<bool(int32_t)> promptCallback,
+        std::function<bool(int32_t, const std::string&)> responseCallback,
+        std::function<bool(bool)> recalculateCallback,
+        PromptContext &ctx) = 0;
+    virtual void setThreadCount(int32_t n_threads) {}
+    virtual int32_t threadCount() { return 1; }
+
+protected:
+    virtual void recalculateContext(PromptContext &promptCtx,
+        std::function<bool(bool)> recalculate) = 0;
+};
+
+#endif // LLMODEL_H