/*
   Copyright (c) 2011, 2015 Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#ifndef NDB_PACK_HPP
#define NDB_PACK_HPP

#include <ndb_global.h>
#include <my_sys.h>
#include <kernel/AttributeHeader.hpp>
#include <NdbSqlUtil.hpp>
#include <NdbEnv.h>
class NdbOut;

/*
 * Pack an array of NDB data values.  The types are specified by an
 * array of data types.  There is no associated table or attribute ids.
 * All or an initial sequence of the specified values are present.
 *
 * Currently used for ordered index keys and bounds in kernel (DBTUX)
 * and in index statistics (mysqld).  The comparison methods use the
 * primitive type comparisons from NdbSqlUtil.
 *
 * Keys and bounds use same spec.  However a value in an index bound can
 * be NULL even if the key attribute is not nullable.  Therefore bounds
 * set the "allNullable" property and have a longer null mask.
 *
 * There are two distinct use occasions: 1) construction of data or
 * bound 2) operating on previously constructed data or bound.  There
 * are classes Data/DataC and Bound/BoundC for these uses.  The latter
 * often can return a result without interpreting the full value.
 *
 * Methods return -1 on error and 0 on success.  Comparison methods
 * assume well-formed data and return negative, zero, positive for less,
 * equal, greater.
 */

class NdbPack {
public:
  class Endian;
  class Type;
  class Spec;
  class Iter;
  class DataC;
  class Data;
  class BoundC;
  class Bound;

  /*
   * Get SQL type.
   */
  static const NdbSqlUtil::Type& getSqlType(Uint32 typeId);

  /*
   * Error codes for core dumps.
   */
  class Error {
  public:
    enum {
      TypeNotSet = -101,          // type id was not set
      TypeOutOfRange = -102,      // type id is out of range
      TypeNotSupported = -103,    // blob (and for now bit) types
      TypeSizeZero = -104,        // max size was set to zero
      TypeFixSizeInvalid = -105,  // fixed size specified wrong
      TypeNullableNotBool = -106, // nullable must be 0 or 1
      CharsetNotSpecified = -107, // char type with no charset number
      CharsetNotFound = -108,     // cannot install in all_charsets[]
      CharsetNotAllowed = -109,   // non-char type with charset
      SpecBufOverflow = -201,     // more spec items than allocated
      DataCntOverflow = -301,     // more data items than in spec
      DataBufOverflow = -302,     // more data bytes than allocated
      DataValueOverflow = -303,   // var length exceeds max size
      DataNotNullable = -304,     // NULL value to not-nullable type
      InvalidAttrInfo = -305,     // invalid plain old attr info
      BoundEmptySide = -401,      // side not 0 for empty bound
      BoundNonemptySide = -402,   // side not -1,+1 for non-empty bound
      InternalError = -901,
      ValidationError = -902,
      NoError = 0
    };
    Error();
    ~Error() {}
    int get_error_code() const;
    int get_error_line() const;

  private:
    friend class Endian;
    friend class Type;
    friend class Spec;
    friend class Iter;
    friend class DataC;
    friend class Data;
    friend class BoundC;
    friend class Bound;
    void set_error(int code, int line) const;
    void set_error(const Error& e2) const;
    mutable int m_error_code;
    mutable int m_error_line;
  };

  /*
   * Endian definitions.
   */
  class Endian {
  public:
    enum Value {
      Native = 0, // replaced by actual value
      Little = 1,
      Big = 2
    };
    static Value get_endian();
    static void convert(void* ptr, Uint32 len);
  };

  /*
   * Data type.
   */
  class Type : public Error {
  public:
    Type();
    Type(int typeId, Uint32 byteSize, bool nullable, Uint32 csNumber);
    ~Type() {}
    /*
     * Define the type.  Size is fixed or max size.  Values of variable
     * length have length bytes.  The definition is verified when the
     * type is added to the specification.  This also installs missing
     * CHARSET_INFO* into all_charsets[].
     */
    void set(Uint32 typeId, Uint32 byteSize, bool nullable, Uint32 csNumber);
    // getters
    Uint32 get_type_id() const;
    Uint32 get_byte_size() const;
    bool get_nullable() const;
    Uint32 get_cs_number() const;
    Uint32 get_array_type() const;
    // print
    friend NdbOut& operator<<(NdbOut&, const Type&);
    void print(NdbOut& out) const;
    const char* print(char* buf, Uint32 bufsz) const;
    int validate() const;

  private:
    friend class Spec;
    friend class Iter;
    friend class DataC;
    friend class Data;
    // verify and complete when added to specification
    int complete();
    Uint16 m_typeId;
    Uint16 m_byteSize;    // fixed or max size in bytes
    Uint16 m_nullable;
    Uint16 m_csNumber;
    Uint16 m_arrayType;   // 0,1,2 length bytes
    Uint16 m_nullbitPos;  // computed as part of Spec
  };

  /*
   * Data specification i.e. array of types.  Usually constructed on the
   * heap, so keep fairly small.  Used for boths keys and bounds.
   */
  class Spec : public Error {
  public:
    Spec();
    ~Spec() {}
    // set initial buffer (calls reset)
    void set_buf(Type* buf, Uint32 bufMaxCnt);
    // use if buffer is relocated
    void set_buf(Type* buf);
    // reset but keep buffer
    void reset();
    // add type to specification once or number of times
    int add(Type type);
    int add(Type type, Uint32 cnt);
    // copy from
    void copy(const Spec& s2);
    // getters (bounds set allNullable)
    const Type& get_type(Uint32 i) const;
    Uint32 get_cnt() const;
    Uint32 get_nullable_cnt(bool allNullable) const;
    Uint32 get_nullmask_len(bool allNullable) const;
    // max data length including null mask
    Uint32 get_max_data_len(bool allNullable) const;
    // minimum var bytes (if used by Data instance)
    Uint32 get_min_var_bytes(bool allNullable) const;
    // print
    friend NdbOut& operator<<(NdbOut&, const Spec&);
    void print(NdbOut& out) const;
    const char* print(char* buf, Uint32 bufsz) const;
    int validate() const;

  private:
    friend class Iter;
    friend class DataC;
    friend class Data;
    friend class BoundC;
    // undefined
    Spec(const Spec&);
    Spec& operator=(const Spec&);
    Type* m_buf;
    Uint16 m_bufMaxCnt;
    Uint16 m_cnt;
    Uint16 m_nullableCnt;
    Uint16 m_varsizeCnt;
    Uint32 m_maxByteSize; // excludes null mask
  };

  /*
   * Iterator over data items.  DataC uses external Iter instances in
   * comparison methods etc.  Data contains an Iter instance which
   * iterates on items added.
   */
  class Iter : public Error {
  public:
    // the data instance is only used to set metadata
    Iter(const DataC& data);
    ~Iter() {}
    void reset();

  private:
    friend class DataC;
    friend class Data;
    friend class BoundC;
    // undefined
    Iter(const Iter&);
    Iter& operator=(const Iter&);
    // describe next non-null or null item and advance iterator
    int desc(const Uint8* item);
    int desc_null();
    // compare current items (DataC buffers are passed)
    int cmp(const Iter& r2, const Uint8* buf1, const Uint8* buf2) const;

    const Spec& m_spec;
    const bool m_allNullable;
    // iterator
    Uint32 m_itemPos;     // position of current item in DataC buffer
    Uint32 m_cnt;         // number of items described so far
    Uint32 m_nullCnt;
    // current item
    Uint32 m_lenBytes;    // 0-2
    Uint32 m_bareLen;     // excludes length bytes
    Uint32 m_itemLen;     // full length, value zero means null
  };

  /*
   * Read-only superclass of Data.  Initialized from a previously
   * constructed Data buffer (any var bytes skipped).  Methods interpret
   * one data item at a time.  Values are native endian.
   */
  class DataC : public Error {
  public:
    DataC(const Spec& spec, bool allNullable);
    // set buffer to previously constructed one with given item count
    void set_buf(const void* buf, Uint32 bufMaxLen, Uint32 cnt);
    // interpret next data item
    int desc(Iter& r) const;
    // compare cnt attrs and also return number of initial equal attrs
    int cmp(const DataC& d2, Uint32 cnt, Uint32& num_eq) const;
    // getters
    const Spec& get_spec() const;
    const void* get_data_buf() const;
    Uint32 get_cnt() const;
    bool is_empty() const;
    bool is_full() const;
    // print
    friend NdbOut& operator<<(NdbOut&, const DataC&);
    void print(NdbOut& out) const;
    const char* print(char* buf, Uint32 bufsz, bool convert_flag = false) const;
    int validate() const { return 0; }

  private:
    friend class Iter;
    friend class Data;
    friend class BoundC;
    // undefined
    DataC(const Data&);
    DataC& operator=(const DataC&);
    const Spec& m_spec;
    const bool m_allNullable;
    const Uint8* m_buf;
    Uint32 m_bufMaxLen;
    // can be updated as part of Data instance
    Uint32 m_cnt;
  };

  /*
   * Instance of an array of data values.  The values are packed into
   * a byte buffer.  The buffer is also maintained as a single varbinary
   * value if non-zero var bytes (length bytes) is specified.
   *
   * Data instances can be received from another source (such as table
   * in database) and may not be native-endian.  Such instances must
   * first be completed with desc_all() and convert().
   */
  class Data : public DataC {
  public:
    Data(const Spec& spec, bool allNullable, Uint32 varBytes);
    // set buffer (calls reset)
    void set_buf(void* buf, Uint32 bufMaxLen);
    // reset but keep buffer (header is zeroed)
    void reset();
    // add non-null data items and return length in bytes
    int add(const void* data, Uint32* len_out);
    int add(const void* data, Uint32 cnt, Uint32* len_out);
    // add null data items and return length 0 bytes
    int add_null(Uint32* len_out);
    int add_null(Uint32 cnt, Uint32* len_out);
    // add from "plain old attr info"
    int add_poai(const Uint32* poai, Uint32* len_out);
    int add_poai(const Uint32* poai, Uint32 cnt, Uint32* len_out);
    // call this before first use
    int finalize();
    // copy from
    int copy(const DataC& d2);
    // convert endian
    int convert(Endian::Value to_endian);
    // create complete instance from buffer contents
    int desc_all(Uint32 cnt, Endian::Value from_endian);
    // getters
    Uint32 get_max_len() const;
    Uint32 get_max_len4() const;
    Uint32 get_var_bytes() const;
    const void* get_full_buf() const;
    Uint32 get_full_len() const;
    Uint32 get_data_len() const;
    Uint32 get_null_cnt() const;
    Endian::Value get_endian() const;
    // print
    friend NdbOut& operator<<(NdbOut&, const Data&);
    void print(NdbOut& out) const;
    const char* print(char* buf, Uint32 bufsz) const;
    int validate() const;

  private:
    friend class Iter;
    friend class Bound;
    // undefined
    Data(const Data&);
    Data& operator=(const Data&);
    int finalize_impl();
    int convert_impl(Endian::Value to_endian);
    const Uint32 m_varBytes;
    Uint8* m_buf;
    Uint32 m_bufMaxLen;
    Endian::Value m_endian;
    // iterator on items added
    Iter m_iter;
  };

  /*
   * Read-only superclass of BoundC, analogous to DataC.  Initialized
   * from a previously constructed Bound or DataC buffer.
   */
  class BoundC : public Error {
  public:
    BoundC(DataC& data);
    ~BoundC() {}
    // call this before first use
    int finalize(int side);
    // compare bound to key (may return 0 if bound is longer)
    int cmp(const DataC& d2, Uint32 cnt, Uint32& num_eq) const;
    // compare bounds (may return 0 if cnt is less than min length)
    int cmp(const BoundC& b2, Uint32 cnt, Uint32& num_eq) const;
    // getters
    DataC& get_data() const;
    int get_side() const;
    // print
    friend NdbOut& operator<<(NdbOut&, const BoundC&);
    void print(NdbOut& out) const;
    const char* print(char* buf, Uint32 bufsz) const;
    int validate() const;

  private:
    friend class Bound;
    // undefined
    BoundC(const BoundC&);
    BoundC& operator=(const BoundC&);
    DataC& m_data;
    int m_side;
  };

  /*
   * Ordered index range bound consists of a partial key and a "side".
   * The partial key is a Data instance where some initial number of
   * values are present.  It is defined separately by the caller and
   * passed to Bound ctor by reference.
   */
  class Bound : public BoundC {
  public:
    Bound(Data& data);
    ~Bound() {}
    void reset();
    // call this before first use
    int finalize(int side);
    // getters
    Data& get_data() const;
    // print
    friend NdbOut& operator<<(NdbOut&, const Bound&);
    void print(NdbOut& out) const;
    const char* print(char* buf, Uint32 bufsz) const;
    int validate() const;

  private:
    // undefined
    Bound(const Bound&);
    Bound& operator=(const Bound&);
    Data& m_data;
  };

  /*
   * Helper for print() methods.
   */
  struct Print {
  private:
    friend class Endian;
    friend class Type;
    friend class Spec;
    friend class Iter;
    friend class DataC;
    friend class Data;
    friend class BoundC;
    friend class Bound;
    Print(char* buf, Uint32 bufsz);
    void print(const char* frm, ...);
    char* m_buf;
    Uint32 m_bufsz;
    Uint32 m_sz;
  };
};

// NdbPack

inline const NdbSqlUtil::Type&
NdbPack::getSqlType(Uint32 typeId)
{
  return NdbSqlUtil::m_typeList[typeId];
}

// NdbPack::Error

inline
NdbPack::Error::Error()
{
  m_error_code = 0;
  m_error_line = 0;
}

// NdbPack::Endian

inline NdbPack::Endian::Value
NdbPack::Endian::get_endian()
{
#ifndef WORDS_BIGENDIAN
  return Little;
#else
  return Big;
#endif
}

// NdbPack::Type

inline
NdbPack::Type::Type()
{
  m_typeId = NDB_TYPE_UNDEFINED;
  m_byteSize = 0;
  m_nullable = true;
  m_csNumber = 0;
  m_arrayType = 0;
  m_nullbitPos = 0;
}

inline
NdbPack::Type::Type(int typeId, Uint32 byteSize, bool nullable, Uint32 csNumber)
{
  set(typeId, byteSize, nullable, csNumber);
}

inline void
NdbPack::Type::set(Uint32 typeId, Uint32 byteSize, bool nullable, Uint32 csNumber)
{
  m_typeId = typeId;
  m_byteSize = byteSize;
  m_nullable = nullable;
  m_csNumber = csNumber;
}

inline Uint32
NdbPack::Type::get_type_id() const
{
  return m_typeId;
}

inline Uint32
NdbPack::Type::get_byte_size() const
{
  return m_byteSize;
}

inline bool
NdbPack::Type::get_nullable() const
{
  return (bool)m_nullable;
}

inline Uint32
NdbPack::Type::get_cs_number() const
{
  return m_csNumber;
}

inline Uint32
NdbPack::Type::get_array_type() const
{
  return m_arrayType;
}

// NdbPack::Spec

inline
NdbPack::Spec::Spec()
{
  reset();
  m_buf = 0;
  m_bufMaxCnt = 0;
}

inline void
NdbPack::Spec::set_buf(Type* buf, Uint32 bufMaxCnt)
{
  reset();
  m_buf = buf;
  m_bufMaxCnt = bufMaxCnt;
}

inline void
NdbPack::Spec::set_buf(Type* buf)
{
  m_buf = buf;
}

inline void
NdbPack::Spec::reset()
{
  m_cnt = 0;
  m_nullableCnt = 0;
  m_varsizeCnt = 0;
  m_maxByteSize = 0;
}

inline const NdbPack::Type&
NdbPack::Spec::get_type(Uint32 i) const
{
  assert(i < m_cnt);
  return m_buf[i];
}

inline Uint32
NdbPack::Spec::get_cnt() const
{
  return m_cnt;
}

inline Uint32
NdbPack::Spec::get_nullable_cnt(bool allNullable) const
{
  if (!allNullable)
    return m_nullableCnt;
  else
    return m_cnt;
}

inline Uint32
NdbPack::Spec::get_nullmask_len(bool allNullable) const
{
  return (get_nullable_cnt(allNullable) + 7) / 8;
}

inline Uint32
NdbPack::Spec::get_max_data_len(bool allNullable) const
{
  return get_nullmask_len(allNullable) + m_maxByteSize;
}

inline Uint32
NdbPack::Spec::get_min_var_bytes(bool allNullable) const
{
  const Uint32 len = get_max_data_len(allNullable);
  return (len < 256 ? 1 : 2);
}

// NdbPack::Iter

inline
NdbPack::Iter::Iter(const DataC& data) :
  m_spec(data.m_spec),
  m_allNullable(data.m_allNullable)
{
  reset();
}

inline void
NdbPack::Iter::reset()
{
  m_itemPos = m_spec.get_nullmask_len(m_allNullable);
  m_cnt = 0;
  m_nullCnt = 0;
  m_lenBytes = 0;
  m_bareLen = 0;
  m_itemLen = 0;
}

// NdbPack::DataC

inline
NdbPack::DataC::DataC(const Spec& spec, bool allNullable) :
  m_spec(spec),
  m_allNullable(allNullable)
{
  m_buf = 0;
  m_bufMaxLen = 0;
  m_cnt = 0;
}

inline void
NdbPack::DataC::set_buf(const void* buf, Uint32 bufMaxLen, Uint32 cnt)
{
  m_buf = static_cast<const Uint8*>(buf);
  m_bufMaxLen = bufMaxLen;
  m_cnt = cnt;
}

inline const NdbPack::Spec&
NdbPack::DataC::get_spec() const
{
  return m_spec;
}

inline const void*
NdbPack::DataC::get_data_buf() const
{
  return &m_buf[0];
}

inline Uint32
NdbPack::DataC::get_cnt() const
{
  return m_cnt;
}

inline bool
NdbPack::DataC::is_empty() const
{
  return m_cnt == 0;
}

inline bool
NdbPack::DataC::is_full() const
{
  return m_cnt == m_spec.m_cnt;
}

// NdbPack::Data

inline
NdbPack::Data::Data(const Spec& spec, bool allNullable, Uint32 varBytes) :
  DataC(spec, allNullable),
  m_varBytes(varBytes),
  m_iter(*this)
{
  m_buf = 0;
  m_bufMaxLen = 0;
  m_endian = Endian::get_endian();
}

inline void
NdbPack::Data::set_buf(void* buf, Uint32 bufMaxLen)
{
  m_buf = static_cast<Uint8*>(buf);
  m_bufMaxLen = bufMaxLen;
  reset();
  assert(bufMaxLen >= m_varBytes);
  DataC::set_buf(&m_buf[m_varBytes], m_bufMaxLen - m_varBytes, 0);
}

inline void
NdbPack::Data::reset()
{
  m_cnt = 0;  // in DataC
  const Uint32 bytes = m_varBytes + m_spec.get_nullmask_len(m_allNullable);
  memset(m_buf, 0, bytes);
  m_endian = Endian::get_endian();
  m_iter.reset();
}

inline int
NdbPack::Data::finalize()
{
  if (m_varBytes == 0 ||
      finalize_impl() == 0)
    return 0;
  return -1;
}

inline int
NdbPack::Data::convert(Endian::Value to_endian)
{
  if (to_endian == Endian::Native)
    to_endian = Endian::get_endian();
  if (m_endian == to_endian)
    return 0;
  if (convert_impl(to_endian) == 0)
  {
    m_endian = to_endian;
    return 0;
  }
  return -1;
}

inline Uint32
NdbPack::Data::get_max_len() const
{
  return m_varBytes + m_spec.get_max_data_len(m_allNullable);
}

inline Uint32
NdbPack::Data::get_max_len4() const
{
  Uint32 len4 = get_max_len();
  len4 += 3;
  len4 /= 4;
  len4 *= 4;
  return len4;
}

inline Uint32
NdbPack::Data::get_var_bytes() const
{
  return m_varBytes;
}

inline const void*
NdbPack::Data::get_full_buf() const
{
  return &m_buf[0];
}

inline Uint32
NdbPack::Data::get_full_len() const
{
  return m_varBytes + m_iter.m_itemPos + m_iter.m_itemLen;
}

inline Uint32
NdbPack::Data::get_data_len() const
{
  return m_iter.m_itemPos + m_iter.m_itemLen;
}

inline Uint32
NdbPack::Data::get_null_cnt() const
{
  return m_iter.m_nullCnt;
}

inline NdbPack::Endian::Value
NdbPack::Data::get_endian() const
{
  return m_endian;
}

// NdbPack::BoundC

inline
NdbPack::BoundC::BoundC(DataC& data) :
  m_data(data)
{
  m_side = 0;
}

inline int
NdbPack::BoundC::cmp(const DataC& d2, Uint32 cnt, Uint32& num_eq) const
{
  const BoundC& b1 = *this;
  const DataC& d1 = b1.m_data;
  int res = d1.cmp(d2, cnt, num_eq);
  if (res == 0 && d1.m_cnt <= d2.m_cnt)
    res = b1.m_side;
  return res;
}

inline NdbPack::DataC&
NdbPack::BoundC::get_data() const
{
  return m_data;
}

inline int
NdbPack::BoundC::get_side() const
{
  return m_side;
}

// NdbPack::Bound

inline
NdbPack::Bound::Bound(Data& data) :
  BoundC(data),
  m_data(data)
{
}

inline void
NdbPack::Bound::reset()
{
  m_data.reset();
  m_side = 0;
}

inline int
NdbPack::Bound::finalize(int side)
{
  if (m_data.finalize() == -1)
  {
    set_error(m_data);
    return -1;
  }
  if (BoundC::finalize(side) == -1)
    return -1;
  return 0;
}

inline NdbPack::Data&
NdbPack::Bound::get_data() const
{
  return m_data;
}

#endif // NDB_PACK_HPP