implement perplexity in llama-server

examples/server/llama-perplexity.sh

@@ -0,0 +1,102 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SERVER="${SERVER:-http://localhost:8080}"
+INPUT_FILE="${1:-}"
+STATE_FILE="${2:-/tmp/perplexity_state.bin}"
+N_CTX="${N_CTX:-512}"
+SAVE_EVERY="${SAVE_EVERY:-10}"
+TMPDIR="${TMPDIR:-/tmp}"
+
+if [[ -z "$INPUT_FILE" ]]; then
+    echo "Usage: $0 <text-file> [state-file]" >&2
+    exit 1
+fi
+
+TOKEN_FILE="$TMPDIR/perplexity_tokens_$$.json"
+REQ_FILE="$TMPDIR/perplexity_req_$$.json"
+trap 'rm -f "$TOKEN_FILE" "$REQ_FILE"' EXIT
+
+jq -s -R '{"content": ., "add_special": true}' < "$INPUT_FILE" > "$REQ_FILE"
+curl -sf -X POST "$SERVER/tokenize" -H "Content-Type: application/json" -d @"$REQ_FILE" > "$TOKEN_FILE" || {
+    echo "[!] Tokenization failed" >&2; exit 1
+}
+
+TOTAL_TOKENS=$(jq -e '.tokens | length' "$TOKEN_FILE")
+N_CHUNKS=$(( TOTAL_TOKENS / N_CTX ))
+
+print_final() {
+    curl -sf "$SERVER/perplexity/state" | jq -r '[.nll, .nll2, .count, .perplexity, .chunk_index] | @tsv' | awk -v n_ctx="$N_CTX" '
+    {
+        nll=$1; nll2=$2; count=$3; ppl=$4; chunk_index=$5;
+        if (count>1) {
+            mean=nll/count;
+            var=(nll2/count)-(mean*mean);
+            if (var>0) {
+                unc=(sqrt(var/(count-1)))*ppl;
+                printf("Final estimate: PPL over %d chunks for n_ctx=%d = %.4lf +/- %.5lf\n", chunk_index, n_ctx, ppl, unc);
+            } else {
+                printf("Final estimate: PPL over %d chunks for n_ctx=%d = %.4lf\n", chunk_index, n_ctx, ppl);
+            }
+        }
+    }'
+}
+
+save_checkpoint() {
+    curl -sf -X POST "$SERVER/perplexity/save" -H "Content-Type: application/json" -d "{\"filename\":\"$STATE_FILE\"}" > /dev/null 2>&1 || true
+}
+
+START_CHUNK=0
+if [[ -f "$STATE_FILE" ]]; then
+    curl -sf -X POST "$SERVER/perplexity/load" -H "Content-Type: application/json" -d "{\"filename\":\"$STATE_FILE\"}" > /dev/null 2>&1 || true
+    START_CHUNK=$(curl -sf "$SERVER/perplexity/state" | jq -r '.chunk_index // 0')
+fi
+
+if (( START_CHUNK >= N_CHUNKS )); then
+    echo "perplexity: calculating perplexity over $N_CHUNKS chunks, n_ctx=$N_CTX, batch_size=$N_CTX, n_seq=1"
+    print_final
+    read -p "Invalidate state and start over? [y/N] " answer < /dev/tty
+    if [[ "$answer" == [yY] ]]; then
+        rm -f "$STATE_FILE"
+        curl -sf -X POST "$SERVER/perplexity/reset" -H "Content-Type: application/json" -d '{}' > /dev/null 2>&1 || true
+        echo "[*] State invalidated. Restart the script to begin from scratch."
+    fi
+    exit 0
+fi
+
+echo "perplexity: calculating perplexity over $N_CHUNKS chunks, n_ctx=$N_CTX, batch_size=$N_CTX, n_seq=1"
+
+shutdown() {
+    echo ""
+    save_checkpoint
+    exit 0
+}
+trap shutdown SIGINT SIGTERM
+
+chunk_idx=$START_CHUNK
+while (( chunk_idx < N_CHUNKS )); do
+    start=$(( chunk_idx * N_CTX ))
+    jq "{\"tokens\": .tokens[$start:$((start + N_CTX))], \"n_ctx\": $N_CTX}" "$TOKEN_FILE" > "$REQ_FILE"
+
+    resp=$(curl -sf -X POST "$SERVER/perplexity" -H "Content-Type: application/json" -d @"$REQ_FILE") || {
+        echo "[!] Request failed at chunk $((chunk_idx + 1))" >&2; exit 1
+    }
+
+    if echo "$resp" | jq -e '.error' > /dev/null 2>&1; then
+        echo "[!] Server error: $(echo "$resp" | jq -c '.error')" >&2; exit 1
+    fi
+
+    idx=$(echo "$resp" | jq -r '.chunk_index')
+    ppl=$(echo "$resp" | jq -r '.perplexity')
+    printf "[%d]%.4lf," "$idx" "$ppl"
+
+    if (( (chunk_idx + 1) % SAVE_EVERY == 0 )); then
+        save_checkpoint
+    fi
+
+    chunk_idx=$((chunk_idx + 1))
+done
+
+echo ""
+print_final
+save_checkpoint