// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "vmo-writer.h"

#include <stdio.h>
#include <cstdarg>
#include <zircon/compiler.h>

namespace devmgr {

void VmoWriter::Printf(const char* fmt, ...) {
    if (status_ != ZX_OK) {
        return;
    }

    char buf[1024];
    va_list ap;
    va_start(ap, fmt);
    vsnprintf(buf, sizeof(buf), fmt, ap);
    va_end(ap);

    const size_t length = strlen(buf);

    if (add_overflow(available_, length, &available_)) {
        status_ = ZX_ERR_INTERNAL;
        return;
    }

    size_t new_written;
    if (add_overflow(written_, length, &new_written) || size_ <= new_written) {
        status_ = ZX_ERR_BUFFER_TOO_SMALL;
        return;
    }

    auto status = vmo_.write(buf, written_, length);
    if (status != ZX_OK) {
        status_ = status;
        printf("Unable to write to vmo. status: %d \n", status);
        return;
    }

    written_ = new_written;
}

}  // namespace devmgr