eccodes/src/grib_buffer.cc

/*
 * (C) Copyright 2005- ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 *
 * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
 * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
 */

/***************************************************************************
 *   Jean Baptiste Filippi - 01.11.2005                                    *
 ***************************************************************************/
#include "grib_api_internal.h"

static void grib_get_buffer_ownership(const grib_context* c, grib_buffer* b)
{
    unsigned char* newdata = NULL;
    if (b->property == CODES_MY_BUFFER)
        return;

    newdata = (unsigned char*)grib_context_malloc(c, b->length);
    memcpy(newdata, b->data, b->length);
    b->data     = newdata;
    b->property = CODES_MY_BUFFER;
}

grib_buffer* grib_create_growable_buffer(const grib_context* c)
{
    grib_buffer* b = (grib_buffer*)grib_context_malloc_clear(c, sizeof(grib_buffer));

    if (b == NULL) {
        grib_context_log(c, GRIB_LOG_ERROR, "%s: cannot allocate buffer", __func__);
        return NULL;
    }

    b->property = CODES_MY_BUFFER;
    b->length   = 10240;
    b->ulength  = 0;
    b->data     = (unsigned char*)grib_context_malloc_clear(c, b->length);
    b->growable = 1;

    if (!b->data) {
        grib_context_log(c, GRIB_LOG_ERROR, "%s: cannot allocate buffer", __func__);
        grib_context_free(c, b);
        return NULL;
    }

    return b;
}

grib_buffer* grib_new_buffer(const grib_context* c, const unsigned char* data, size_t buflen)
{
    grib_buffer* b = (grib_buffer*)grib_context_malloc_clear(c, sizeof(grib_buffer));

    if (b == NULL) {
        grib_context_log(c, GRIB_LOG_ERROR, "%s: cannot allocate buffer", __func__);
        return NULL;
    }

    b->property     = CODES_USER_BUFFER;
    b->length       = buflen;
    b->ulength      = buflen;
    b->ulength_bits = buflen * 8;
    b->data         = (unsigned char*)data;

    return b;
}

void grib_buffer_delete(const grib_context* c, grib_buffer* b)
{
    if (b->property == CODES_MY_BUFFER)
        grib_context_free(c, b->data);
    b->length  = 0;
    b->ulength = 0;
    grib_context_free(c, b);
}

static void grib_grow_buffer_to(const grib_context* c, grib_buffer* b, size_t ns)
{
    if (ns > b->length) {
        grib_get_buffer_ownership(c, b);
        unsigned char* newdata = (unsigned char*)grib_context_malloc_clear(c, ns);
        memcpy(newdata, b->data, b->length);
        grib_context_free(c, b->data);
        b->data   = newdata;
        b->length = ns;
    }
}

void grib_grow_buffer(const grib_context* c, grib_buffer* b, size_t new_size)
{
    if (new_size > b->length) {
        size_t len = 0;
        size_t inc = b->length > 2048 ? b->length : 2048;
        len        = ((new_size + 2 * inc) / 1024) * 1024;
        grib_grow_buffer_to(c, b, len);
    }
}

void grib_buffer_set_ulength_bits(const grib_context* c, grib_buffer* b, size_t length_bits)
{
    size_t length = length_bits / 8;
    if (length_bits % 8)
        length++;
    grib_grow_buffer(c, b, length);
    b->ulength_bits = length_bits;
    b->ulength      = length;
}

void grib_buffer_set_ulength(const grib_context* c, grib_buffer* b, size_t length)
{
    grib_grow_buffer(c, b, length);
    b->ulength      = length;
    b->ulength_bits = length * 8;
}

static void update_offsets(grib_accessor* a, long len)
{
    while (a) {
        grib_section* s = a->sub_section;
        a->offset += len;
        grib_context_log(a->context, GRIB_LOG_DEBUG, "::::: grib_buffer : accessor %s is moving by %d bytes to %ld", a->name, len, a->offset);
        if (s)
            update_offsets(s->block->first, len);
        a = a->next;
    }
}

static void update_offsets_after(grib_accessor* a, long len)
{
    while (a) {
        update_offsets(a->next, len);
        a = a->parent->owner;
    }
}

// void grib_recompute_sections_lengths(grib_section* s)
// {
//     if(s)
//     {
//         long   plen = 0;
//         size_t  len = 1;
//         grib_accessor* a = s->block->first;
//         while(a)
//         {
//             /* grib_recompute_sections_lengths(grib_get_sub_section(a)); */
//             grib_recompute_sections_lengths(a->sub_section);
//             a = a->next;
//         }
//         if(s->aclength)
//         {
//             int ret;
//             if(s->owner)
//                 plen = grib_get_next_position_offset(s->block->last) - s->owner->offset;
//             else
//                 plen = grib_get_next_position_offset(s->block->last);
//             if((ret = grib_pack_long(s->aclength, &plen, &len)) != GRIB_SUCCESS)
//                 ;
//
//             if(s->h->context->debug)
//                 printf("SECTION updating length %ld .. %s\n",plen,s->owner->name);
//         }
//     }
// }

// /* new GCC compiler v4.5.0 complains function is defined but not used*/
// static void update_sections_lengths(grib_section* s)
// {
//     long   plen = 0;
//     size_t  len = 1;
//     if(!s) return;
//     if(s->aclength)
//     {
//         int ret;
//         if(s->owner)
//             plen = grib_get_next_position_offset(s->block->last) - s->owner->offset;
//         else
//             plen = grib_get_next_position_offset(s->block->last);
//         /* if(s->owner) */
//         /* s->owner->length = plen; */
//         /* if(s->aclength)  */
//         if((ret = grib_pack_long(s->aclength, &plen, &len)) != GRIB_SUCCESS)
//             ;
//         if(s->h->context->debug)
//         {
//             printf("SECTION updating length %ld .. %s\n",plen,s->owner->name);
//             printf("NEXT_POS = %ld, owner offset= %ld %s %s\n",
//                     grib_get_next_position_offset(s->block->last),
//                     s->owner ? s->owner->offset : 0L, s->owner->name,
//                             s->block->last->name);
//         }
//     }
//     if(s->owner)
//         update_sections_lengths(s->owner->parent);
// }

int grib_buffer_replace(grib_accessor* a, const unsigned char* data,
                        size_t newsize, int update_lengths, int update_paddings)
{
    size_t offset = a->offset;
    long oldsize  = grib_get_next_position_offset(a) - offset;
    long increase = (long)newsize - (long)oldsize;

    grib_buffer* buffer   = grib_handle_of_accessor(a)->buffer;
    size_t message_length = buffer->ulength;

    grib_context_log(a->context, GRIB_LOG_DEBUG,
                     "grib_buffer_replace %s offset=%ld oldsize=%ld newsize=%ld message_length=%ld update_paddings=%d",
                     a->name, (long)offset, oldsize, (long)newsize, (long)message_length, update_paddings);

    grib_buffer_set_ulength(a->context,
                            buffer,
                            buffer->ulength + increase);

    /* move the end */
    if (increase)
        memmove(
            buffer->data + offset + newsize,
            buffer->data + offset + oldsize,
            message_length - offset - oldsize);

    /* copy new data */
    DEBUG_ASSERT(buffer->data + offset);
    DEBUG_ASSERT(data || (newsize == 0)); /* if data==NULL then newsize must be 0 */
    if (data) {
        /* Note: memcpy behaviour is undefined if either dest or src is NULL */
        memcpy(buffer->data + offset, data, newsize);
    }

    if (increase) {
        update_offsets_after(a, increase);
        if (update_lengths) {
            grib_update_size(a, newsize);
            int err = grib_section_adjust_sizes(grib_handle_of_accessor(a)->root, 1, 0);
            if (err) return err;
            if (update_paddings)
                grib_update_paddings(grib_handle_of_accessor(a)->root);
        }
    }
    return GRIB_SUCCESS;
}

void grib_update_sections_lengths(grib_handle* h)
{
    grib_section_adjust_sizes(h->root, 2, 0);
    grib_update_paddings(h->root);
}