server : remove n_past (#16818)

* server : remove n_past

* server : replace slot.n_prompt_tokens() with slot.task->n_tokens()

* server : fixes + clean-up

* cont : fix context shift

* server : add server_tokens::pos_next()

Co-authored-by: Xuan-Son Nguyen <son@huggingface.co>

* server : fix pos_next() usage

Co-authored-by: Xuan-Son Nguyen <son@huggingface.co>

---------

Co-authored-by: Xuan-Son Nguyen <son@huggingface.co>
This commit is contained in:
Georgi Gerganov
2025-10-30 18:42:57 +02:00
committed by GitHub
parent 517b7170e1
commit b52edd2558
3 changed files with 177 additions and 153 deletions

View File

@@ -1080,19 +1080,22 @@ struct server_tokens {
private: // disallow accessing these members directly, risking out-of-sync
// map a **start** position in tokens to the image chunk
std::unordered_map<llama_pos, mtmd::input_chunk_ptr> map_pos_to_media;
// map a **start** index in tokens to the image chunk
// note: the order need to be in-sync with tokens
std::map<size_t, mtmd::input_chunk_ptr> map_idx_to_media;
// list of tokens
// it can include LLAMA_TOKEN_NULL, which is used to indicate a token that is not a text token
// a mtmd_input_chunk can occupy multiple tokens, one llama_token per **position**
// important: for models using mrope, an image can contain multiple tokens but will use only one **position**
// if the token is LLAMA_TOKEN_NULL, it indicates that this position is occupied by media chunk
// otherwise, it is a normal text token
// note: a non-text chunk can occupy multiple tokens (aka memory cells) in the token list
// note(2): for M-RoPE, an image can occupy different number of pos; do not assume 1-to-1 mapping tokens <-> pos
llama_tokens tokens;
// for ex. with input of 5 text tokens and 2 images:
// [0] [1] [2] [3] [4] [img0] [img0] [img0] [img1] [img1]
// pos 0 1 2 3 4 5 6 7 8 9
// map_pos_to_media will contain: {5, img0}, {8, img1}
// for ex. with input of 5 text tokens and 2 images (each image occupies 3 tokens and 2 pos):
// [0] [1] [2] [3] [4] [img0] [img0] [img0] [img1] [img1] [img1]
// idx 0 1 2 3 4 5 6 7 8 9 10
// pos 0 1 2 3 4 5 5 5 7 7 7
// map_idx_to_media will contain: {5, img0}, {8, img1}
public:
server_tokens() = default;
@@ -1117,13 +1120,31 @@ public:
}
}
server_tokens(const llama_tokens & tokens, bool has_mtmd) : has_mtmd(has_mtmd), tokens(tokens) {}
server_tokens(const llama_tokens & tokens, bool has_mtmd) : has_mtmd(has_mtmd), tokens(tokens) {
}
llama_pos pos_next() const {
if (!has_mtmd) {
return tokens.size();
}
llama_pos res = tokens.size();
for (auto it = map_idx_to_media.begin(); it != map_idx_to_media.end(); ++it) {
const auto & chunk = it->second;
res += mtmd_input_chunk_get_n_pos(chunk.get()) - mtmd_input_chunk_get_n_tokens(chunk.get());
}
return res;
}
// for debugging
std::string str() const {
std::ostringstream oss;
oss << "tokens: ";
for (const auto & t : tokens) {
for (size_t idx = 0; idx < tokens.size(); ++idx) {
llama_token t = tokens[idx];
oss << "idx:" << idx << " ";
if (t == LLAMA_TOKEN_NULL) {
oss << "<embd> ";
} else {
@@ -1131,16 +1152,16 @@ public:
}
}
oss << "\n";
oss << "image pos: ";
for (const auto & it : map_pos_to_media) {
oss << "image idx: ";
for (const auto & it : map_idx_to_media) {
oss << it.first << ", ";
}
return oss.str();
}
const mtmd::input_chunk_ptr & find_chunk(llama_pos pos) const {
auto it = map_pos_to_media.find(pos);
if (it != map_pos_to_media.end()) {
const mtmd::input_chunk_ptr & find_chunk(size_t idx) const {
auto it = map_idx_to_media.find(idx);
if (it != map_idx_to_media.end()) {
return it->second;
}
throw std::runtime_error("Chunk not found");
@@ -1158,13 +1179,13 @@ public:
auto type = mtmd_input_chunk_get_type(chunk);
if (type == MTMD_INPUT_CHUNK_TYPE_IMAGE || type == MTMD_INPUT_CHUNK_TYPE_AUDIO) {
GGML_ASSERT(has_mtmd);
const int n_pos = mtmd_input_chunk_get_n_pos(chunk);
llama_pos start_pos = tokens.size();
for (int i = 0; i < n_pos; ++i) {
const size_t n_tokens = mtmd_input_chunk_get_n_tokens(chunk);
size_t start_idx = tokens.size();
for (size_t i = 0; i < n_tokens; ++i) {
tokens.emplace_back(LLAMA_TOKEN_NULL);
}
mtmd::input_chunk_ptr new_chunk(mtmd_input_chunk_copy(chunk));
map_pos_to_media[start_pos] = std::move(new_chunk);
map_idx_to_media[start_idx] = std::move(new_chunk);
} else if (type == MTMD_INPUT_CHUNK_TYPE_TEXT) {
size_t n_tokens;
const auto * text_tokens = mtmd_input_chunk_get_tokens_text(chunk, &n_tokens);
@@ -1178,7 +1199,7 @@ public:
// appends server tokens, updates the media map. copies media chunks.
void push_back(server_tokens & tokens) {
size_t start_pos = size();
size_t start_idx = size();
for (size_t i = 0; i < tokens.size(); i++) {
push_back(tokens[i]);
}
@@ -1186,10 +1207,10 @@ public:
// Assert if we are copying MTMD chunks to a server_tokens that does not have mtmd.
// We could also just check, but this will prevent silently dropping MTMD data.
GGML_ASSERT(has_mtmd);
for (auto it = tokens.map_pos_to_media.begin(); it != tokens.map_pos_to_media.end(); ) {
auto * chunk = tokens.map_pos_to_media[it->first].get();
for (auto it = tokens.map_idx_to_media.begin(); it != tokens.map_idx_to_media.end(); ) {
auto * chunk = tokens.map_idx_to_media[it->first].get();
mtmd::input_chunk_ptr new_chunk(mtmd_input_chunk_copy(chunk));
map_pos_to_media[start_pos+it->first] = std::move(new_chunk);
map_idx_to_media[start_idx+it->first] = std::move(new_chunk);
}
}
}
@@ -1245,10 +1266,10 @@ public:
}
}
// remove all image chunks that are not used anymore
for (auto it = map_pos_to_media.begin(); it != map_pos_to_media.end(); ) {
llama_pos pos = it->first;
if (pos >= (llama_pos)n) {
it = map_pos_to_media.erase(it);
for (auto it = map_idx_to_media.begin(); it != map_idx_to_media.end(); ) {
size_t idx = it->first;
if (idx >= n) {
it = map_idx_to_media.erase(it);
} else {
++it;
}
@@ -1296,12 +1317,12 @@ public:
const std::string id_ai = mtmd_input_chunk_get_id(a_chunk.get());
const std::string id_bi = mtmd_input_chunk_get_id(b_chunk.get());
const size_t pos_a = mtmd_input_chunk_get_n_pos(a_chunk.get());
const size_t pos_b = mtmd_input_chunk_get_n_pos(b_chunk.get());
const size_t n_tok_a = mtmd_input_chunk_get_n_tokens(a_chunk.get());
const size_t n_tok_b = mtmd_input_chunk_get_n_tokens(b_chunk.get());
if (id_ai == id_bi && pos_a == pos_b) {
GGML_ASSERT(pos_a > 0 && "Invalid media chunk"); // should never happen
i += pos_a - 1; // will be +1 by the for loop
if (id_ai == id_bi && n_tok_a == n_tok_b) {
GGML_ASSERT(n_tok_a > 0 && "Invalid media chunk"); // should never happen
i += n_tok_a - 1; // will be +1 by the for loop
continue;
}
@@ -1329,8 +1350,8 @@ public:
if (t == LLAMA_TOKEN_NULL) {
try {
const auto & chunk = find_chunk(i);
size_t n_pos = mtmd_input_chunk_get_n_pos(chunk.get());
i += n_pos - 1; // will be +1 by the for loop
size_t n_tokens = mtmd_input_chunk_get_n_tokens(chunk.get());
i += n_tokens - 1; // will be +1 by the for loop
} catch (const std::exception & e) {
return false;
}
@@ -1345,19 +1366,20 @@ public:
int32_t process_chunk(
llama_context * ctx,
mtmd_context * mctx,
llama_pos n_past,
size_t idx,
llama_pos pos,
int32_t seq_id,
llama_pos & n_pos_out) const {
const auto & chunk = find_chunk(n_past);
size_t & n_tokens_out) const {
const auto & chunk = find_chunk(idx);
const char * name = mtmd_input_chunk_get_type(chunk.get()) == MTMD_INPUT_CHUNK_TYPE_IMAGE
? "image" : "audio";
SRV_INF("processing %s...\n", name);
int32_t n_batch = llama_n_batch(ctx);
int64_t t0 = ggml_time_ms();
llama_pos new_n_past = n_past;
llama_pos new_n_past; // unused for now
int32_t result = mtmd_helper_eval_chunk_single(mctx, ctx,
chunk.get(),
n_past,
pos,
seq_id,
n_batch,
true, // logits last
@@ -1365,10 +1387,10 @@ public:
SRV_INF("%s processed in %" PRId64 " ms\n", name, ggml_time_ms() - t0);
if (result != 0) {
LOG_ERR("mtmd_helper_eval failed with status %d", result);
n_pos_out = n_past;
n_tokens_out = 0;
return result;
}
n_pos_out = new_n_past;
n_tokens_out = mtmd_input_chunk_get_n_tokens(chunk.get());
return 0;
}
};