llama : add session file format and saved sessions in main (#1169)

1 files changed, 53 insertions, 0 deletions

diff --git a/llama.cpp b/llama.cpp
index bfebf14b..dca017db 100644
--- a/llama.cpp
+++ b/llama.cpp
@@ -2431,3 +2431,56 @@ std::vector<std::pair<std::string, struct ggml_tensor *>>& llama_internal_get_te
     return ctx->model.tensors_by_name;
 }
 
+size_t llama_load_session_file(struct llama_context * ctx, const char * path_session, llama_token * tokens_out, size_t n_token_capacity, size_t * n_token_count_out) {
+    // TODO leverage mmap
+    llama_file file(path_session, "rb");
+    const uint32_t magic = file.read_u32();
+    const uint32_t version = file.read_u32();
+
+    if (!(magic == 'ggsn' && version == 0)) {
+        fprintf(stderr, "%s : unknown (magic, version) for session file: %08x, %08x\n", __func__, magic, version);
+        return 0;
+    }
+
+    llama_hparams session_hparams;
+    file.read_raw(&session_hparams, sizeof(llama_hparams));
+
+    // REVIEW
+    if (session_hparams != ctx->model.hparams) {
+        fprintf(stderr, "%s : model hparams didn't match from session file!\n", __func__);
+        return 0;
+    }
+
+    const uint32_t n_token_count = file.read_u32();
+    LLAMA_ASSERT(n_token_capacity >= n_token_count);
+    file.read_raw(tokens_out, sizeof(llama_token) * n_token_count);
+    *n_token_count_out = n_token_count;
+
+    const size_t n_state_size = file.size - file.tell();
+    const size_t n_orig_state_size = llama_get_state_size(ctx);
+    if (n_state_size != n_orig_state_size) {
+        fprintf(stderr, "%s : failed to validate state size\n", __func__);
+    }
+    std::unique_ptr<uint8_t[]> state_data(new uint8_t[n_state_size]);
+    file.read_raw(state_data.get(), n_state_size);
+    return llama_set_state_data(ctx, state_data.get());
+}
+
+size_t llama_save_session_file(struct llama_context * ctx, const char * path_session, const llama_token * tokens, size_t n_token_count) {
+    // TODO save temp & swap
+    llama_file file(path_session, "wb");
+
+    const size_t n_state_size = llama_get_state_size(ctx);
+    std::unique_ptr<uint8_t[]> state_data(new uint8_t[n_state_size]);
+    llama_copy_state_data(ctx, state_data.get());
+
+    file.write_u32('ggsn'); // magic
+    file.write_u32(0); // version
+    file.write_raw(&ctx->model.hparams, sizeof(llama_hparams));
+
+    file.write_u32((uint32_t) n_token_count); // REVIEW
+    file.write_raw(tokens, sizeof(llama_token) * n_token_count);
+
+    file.write_raw(state_data.get(), n_state_size);
+    return n_state_size; // REVIEW
+}