Add streaming for omnivlm (#39)

* omni vlm add streaming

* omni vlm add streaming

examples/omni-vlm/omni-vlm-wrapper.cpp

@@ -15,10 +15,10 @@
 #include <vector>
 #include <string>
 #include <iostream>
+#include <memory>
 
 #include "omni-vlm-wrapper.h"
 
-
 struct omnivlm_context {
     struct clip_ctx * ctx_clip = NULL;
     struct llama_context * ctx_llama = NULL;
@@ -30,6 +30,53 @@ void* internal_chars = nullptr;
 static struct common_params params;
 static struct llama_model* model;
 static struct omnivlm_context* ctx_omnivlm;
+static std::unique_ptr<struct omni_streaming_sample> g_oss = nullptr;
+
+static bool eval_id(struct llama_context * ctx_llama, int id, int * n_past);
+static void omnivlm_free(struct omnivlm_context * ctx_omnivlm);
+
+struct omni_streaming_sample {
+    struct common_sampler * ctx_sampling_;
+    std::string image_;
+    std::string ret_str_;
+    int32_t n_past_;
+    int32_t dec_cnt_;
+
+    omni_streaming_sample() = delete;
+    omni_streaming_sample(const std::string& image)
+            :image_(image) {
+        n_past_ = 0;
+        dec_cnt_ = 0;
+        params.sparams.top_k = 1;
+        params.sparams.top_p = 1.0f;
+        ctx_sampling_ = common_sampler_init(model, params.sparams);
+    }
+
+    int32_t sample() {
+        const llama_token id = common_sampler_sample(ctx_sampling_, ctx_omnivlm->ctx_llama, -1);
+        common_sampler_accept(ctx_sampling_, id, true);
+        if (llama_token_is_eog(llama_get_model(ctx_omnivlm->ctx_llama), id)) {
+            ret_str_ = "</s>";
+        } else {
+            ret_str_ = common_token_to_piece(ctx_omnivlm->ctx_llama, id);
+        }
+        eval_id(ctx_omnivlm->ctx_llama, id, &n_past_);
+
+        ++dec_cnt_;
+        return id;
+    }
+
+    ~omni_streaming_sample() {
+        common_sampler_free(ctx_sampling_);
+        if(ctx_omnivlm != nullptr) {
+            ctx_omnivlm->model = nullptr;
+            omnivlm_free(ctx_omnivlm);
+            free(ctx_omnivlm);
+            ctx_omnivlm = nullptr;
+        }
+    }
+};
+
 
 static struct omni_image_embed * load_image(omnivlm_context * ctx_omnivlm, common_params * params, const std::string & fname) {
 
@@ -286,3 +333,81 @@ void omnivlm_free() {
     }
     llama_free_model(model);
 }
+
+
+struct omni_streaming_sample* omnivlm_inference_streaming(const char *prompt, const char *imag_path) {
+    if (g_oss) {
+        g_oss.reset();
+    }
+    g_oss = std::make_unique<omni_streaming_sample>(std::string(imag_path));
+
+    ctx_omnivlm = omnivlm_init_context(&params, model);
+
+    params.prompt = prompt;
+
+    if (params.omni_vlm_version == "vlm-81-ocr") {
+        params.prompt = "<|im_start|>system\nYou are Nano-Omni-VLM, created by Nexa AI. You are a helpful assistant.<|im_end|>\n<|im_start|>user\n <|ocr_start|><|vision_start|><|image_pad|><|vision_end|><|ocr_end|><|im_end|>";
+    } else if (params.omni_vlm_version == "vlm-81-instruct" || params.omni_vlm_version == "nano-vlm-instruct") {
+        params.prompt = "<|im_start|>system\nYou are Nano-Omni-VLM, created by Nexa AI. You are a helpful assistant.<|im_end|>\n<|im_start|>user\n\n<|vision_start|><|image_pad|><|vision_end|>" + params.prompt + "<|im_end|>";
+    } else {
+        LOG_ERR("%s : error: you set wrong vlm version info:'%s'.\n", __func__, params.omni_vlm_version.c_str());
+        throw std::runtime_error("You set wrong vlm_version info strings.");
+    }
+
+    return g_oss.get();
+}
+
+int32_t sample(omni_streaming_sample* oss) {
+    const int max_tgt_len = params.n_predict < 0 ? 256 : params.n_predict;
+    int32_t ret_id;
+    if(oss->n_past_ == 0) {
+        auto * image_embed = load_image(ctx_omnivlm, &params, oss->image_);
+        if (!image_embed) {
+            LOG_ERR("%s: failed to load image %s. Terminating\n\n", __func__, oss->image_.c_str());
+            throw std::runtime_error("failed to load image " + oss->image_);
+        }
+
+        size_t image_pos = params.prompt.find("<|image_pad|>");
+        std::string system_prompt, user_prompt;
+
+        system_prompt = params.prompt.substr(0, image_pos);
+        user_prompt = params.prompt.substr(image_pos + std::string("<|image_pad|>").length());
+        if (params.verbose_prompt) {
+            auto tmp = ::common_tokenize(ctx_omnivlm->ctx_llama, system_prompt, true, true);
+            for (int i = 0; i < (int) tmp.size(); i++) {
+                LOG_ERR("%6d -> '%s'\n", tmp[i], common_token_to_piece(ctx_omnivlm->ctx_llama, tmp[i]).c_str());
+            }
+        }
+        if (params.verbose_prompt) {
+            auto tmp = ::common_tokenize(ctx_omnivlm->ctx_llama, user_prompt, true, true);
+            for (int i = 0; i < (int) tmp.size(); i++) {
+                LOG_ERR("%6d -> '%s'\n", tmp[i], common_token_to_piece(ctx_omnivlm->ctx_llama, tmp[i]).c_str());
+            }
+        }
+
+        eval_string(ctx_omnivlm->ctx_llama, system_prompt.c_str(), params.n_batch, &(oss->n_past_), true);
+        omnivlm_eval_image_embed(ctx_omnivlm->ctx_llama, image_embed, params.n_batch, &(oss->n_past_));
+        eval_string(ctx_omnivlm->ctx_llama, user_prompt.c_str(), params.n_batch, &(oss->n_past_), false);
+
+        omnivlm_image_embed_free(image_embed);
+
+        ret_id = oss->sample();
+        if (oss->ret_str_ == "<|im_end|>" || oss->ret_str_ == "</s>" ) {
+            ret_id = -1;
+        }
+    } else {
+        if(oss->dec_cnt_ == max_tgt_len) {
+            ret_id = -2;
+        } else {
+            ret_id = oss->sample();
+            if (oss->ret_str_ == "<|im_end|>" || oss->ret_str_ == "</s>" ) {
+                ret_id = -1;
+            }
+        }
+    }
+    return ret_id;
+}
+
+const char* get_str(omni_streaming_sample* oss) {
+    return oss->ret_str_.c_str();
+}

examples/omni-vlm/omni-vlm-wrapper.h

@@ -1,6 +1,6 @@
-
 #ifndef OMNIVLMWRAPPER_H
 #define OMNIVLMWRAPPER_H
+#include <stdint.h>
 
 #ifdef LLAMA_SHARED
 #    if defined(_WIN32) && !defined(__MINGW32__)
@@ -20,14 +20,22 @@
 extern "C" {
 #endif
 
+struct omni_streaming_sample;
+
 OMNIVLM_API void omnivlm_init(const char* llm_model_path, const char* projector_model_path, const char* omni_vlm_version);
 
 OMNIVLM_API const char* omnivlm_inference(const char* prompt, const char* imag_path);
 
+OMNIVLM_API struct omni_streaming_sample* omnivlm_inference_streaming(const char* prompt, const char* imag_path);
+
+OMNIVLM_API int32_t sample(struct omni_streaming_sample *);
+
+OMNIVLM_API const char* get_str(struct omni_streaming_sample *);
+
 OMNIVLM_API void omnivlm_free();
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif
+#endif