Function agent_read_range

ds4_agent.c:5654–5726

Read file text for the model. Normal mode shows plain line numbers. Raw * mode is reserved for cases where line decoration would corrupt the payload * being inspected. */

    if (!title) return xstrdup("(no user prompt)");
    size_t len = strlen(title);
    if (max_bytes == 0 || len <= max_bytes) return xstrdup(title);
    if (max_bytes < 4) max_bytes = 4;
    agent_buf b = {0};
    agent_buf_append(&b, title, max_bytes - 3);
    agent_buf_puts(&b, "...");
    return agent_buf_take(&b);
}

static char *agent_session_title_from_file(const char *path, size_t max_bytes) {
    FILE *fp = fopen(path, "rb");
    if (!fp) return xstrdup("(unreadable session)");
    ds4_kvstore_entry hdr = {0};
    uint32_t text_bytes = 0;
    char *text = NULL;
    char *trailer_title = NULL;
    bool ok = ds4_kvstore_read_header(fp, &hdr, &text_bytes) &&
              agent_kv_read_text(fp, text_bytes, &text, NULL, 0);
    if (ok && (hdr.ext_flags & DS4_KVSTORE_EXT_SESSION_TITLE))
        ok = agent_kv_read_title_trailer(fp, &hdr, &trailer_title, NULL, 0);
    fclose(fp);
    char *title = ok ?
        (trailer_title ?
            agent_session_title_clip(trailer_title, max_bytes) :
            agent_session_title_from_text(text, text_bytes, max_bytes)) :
        xstrdup("(unreadable session)");
    free(trailer_title);
    free(text);
    return title;
}

#define AGENT_HISTORY_DEFAULT_TURNS 3
#define AGENT_HISTORY_MAX_TURNS 200
#define AGENT_HISTORY_ASSISTANT_MAX_LINES 80
#define AGENT_HISTORY_ASSISTANT_MAX_BYTES 12000

typedef enum {
    AGENT_HISTORY_MARK_NONE,
    AGENT_HISTORY_MARK_USER,
    AGENT_HISTORY_MARK_ASSISTANT,
    AGENT_HISTORY_MARK_EOS,
} agent_history_mark;

typedef struct {
    const char **v;
    agent_history_mark *mark;
    int len;
    int cap;
} agent_history_ptrs;

static void agent_history_ptrs_push(agent_history_ptrs *p, const char *s,
                                    agent_history_mark mark) {
    if (p->len == p->cap) {
        p->cap = p->cap ? p->cap * 2 : 16;
        p->v = xrealloc(p->v, (size_t)p->cap * sizeof(p->v[0]));
        p->mark = xrealloc(p->mark, (size_t)p->cap * sizeof(p->mark[0]));
    }
    p->v[p->len] = s;
    p->mark[p->len] = mark;