root/lang/c/msgpack/trunk/cpp/unpack.cpp @ 18666

#include "msgpack/unpack.hpp"
#include "unpack_context.hpp"
#include <stdlib.h>

namespace msgpack {

struct unpacker::context {
        context(zone* z)
        {
                msgpack_unpacker_init(&m_ctx);
                m_ctx.user = z;
        }

        ~context() { }

        int execute(const void* data, size_t len, size_t* off)
        {
                return msgpack_unpacker_execute(&m_ctx, (const char*)data, len, off);
        }

        object_class* data()
        {
                return msgpack_unpacker_data(&m_ctx);
        }

        void reset()
        {
                zone* z = m_ctx.user;
                msgpack_unpacker_init(&m_ctx);
                m_ctx.user = z;
        }

        void reset(zone* z)
        {
                msgpack_unpacker_init(&m_ctx);
                m_ctx.user = z;
        }

        zone* user()
        {
                return m_ctx.user;
        }

        void user(zone* z)
        {
                m_ctx.user = z;
        }

private:
        msgpack_unpacker m_ctx;

private:
        context();
        context(const context&);
};


unpacker::unpacker() :
        m_zone(new zone()),
        m_ctx(new context(m_zone)),
        m_buffer(NULL),
        m_used(0),
        m_free(0),
        m_off(0)
{ }


unpacker::~unpacker()
{
        free(m_buffer);
        delete m_ctx;
        delete m_zone;
}


void unpacker::expand_buffer(size_t len)
{
        if(m_off == 0) {
                size_t next_size;
                if(m_free != 0) { next_size = m_free * 2; }
                else { next_size = MSGPACK_UNPACKER_INITIAL_BUFFER_SIZE; }
                while(next_size < len + m_used) { next_size *= 2; }

                // FIXME realloc?
                void* tmp = malloc(next_size);
                if(!tmp) { throw std::bad_alloc(); }
                memcpy(tmp, m_buffer, m_used);

                free(m_buffer);
                m_buffer = tmp;
                m_free = next_size - m_used;

        } else {
                size_t next_size = MSGPACK_UNPACKER_INITIAL_BUFFER_SIZE;
                while(next_size < len + m_used - m_off) { next_size *= 2; }

                void* tmp = malloc(next_size);
                if(!tmp) { throw std::bad_alloc(); }
                memcpy(tmp, ((char*)m_buffer)+m_off, m_used-m_off);

                try {
                        m_zone->push_finalizer<void>(&zone::finalize_free, NULL, m_buffer);
                } catch (...) {
                        free(tmp);
                        throw;
                }

                m_buffer = tmp;
                m_used = m_used - m_off;
                m_free = next_size - m_used;
                m_off = 0;
        }
}

bool unpacker::execute()
{
        int ret = m_ctx->execute(m_buffer, m_used, &m_off);
        if(ret < 0) {
                throw unpack_error("parse error");
        } else if(ret == 0) {
                return false;
        } else {
                expand_buffer(0);
                return true;
        }
}

zone* unpacker::release_zone()
{
        zone* nz = new zone();
        zone* z = m_zone;
        m_zone = nz;
        m_ctx->user(m_zone);
        return z;
}

object unpacker::data()
{
        return object(m_ctx->data());
}

void unpacker::reset()
{
        if(m_off != 0) { expand_buffer(0); }
        if(!m_zone->empty()) {
                delete m_zone;
                m_zone = NULL;
                m_zone = new zone();
        }
        m_ctx->reset();
}


object unpacker::unpack(const void* data, size_t len, zone& z)
{
        context ctx(&z);
        size_t off = 0;
        int ret = ctx.execute(data, len, &off);
        if(ret < 0) {
                throw unpack_error("parse error");
        } else if(ret == 0) {
                throw unpack_error("insufficient bytes");
        } else if(off < len) {
                throw unpack_error("extra bytes");
        }
        return ctx.data();
}


}  // namespace msgpack