Finished merging wl5986 started by Igor.

1 files changed, 344 insertions, 245 deletions

diff --git a/sql/sp_rcontext.h b/sql/sp_rcontext.h
index dd1d625a46c..00fbf3e13ab 100644
--- a/sql/sp_rcontext.h
+++ b/sql/sp_rcontext.h
@@ -22,80 +22,18 @@
 #endif
 
 #include "sql_class.h"                    // select_result_interceptor
+#include "sp_pcontext.h"                  // sp_condition_value
+
+///////////////////////////////////////////////////////////////////////////
+// sp_rcontext declaration.
+///////////////////////////////////////////////////////////////////////////
 
-struct sp_cond_type;
 class sp_cursor;
-struct sp_variable;
 class sp_lex_keeper;
 class sp_instr_cpush;
 class Query_arena;
 class sp_head;
-class sp_pcontext;
 class Item_cache;
-typedef class st_select_lex_unit SELECT_LEX_UNIT;
-class Server_side_cursor;
-
-#define SP_HANDLER_NONE      0
-#define SP_HANDLER_EXIT      1
-#define SP_HANDLER_CONTINUE  2
-#define SP_HANDLER_UNDO      3
-
-typedef struct
-{
-  /** Condition caught by this HANDLER. */
-  struct sp_cond_type *cond;
-  /** Location (instruction pointer) of the handler code. */
-  uint handler;
-  /** Handler type (EXIT, CONTINUE). */
-  int type;
-} sp_handler_t;
-
-typedef struct
-{
-  /** Instruction pointer of the active handler. */
-  uint ip;
-  /** Handler index of the active handler. */
-  uint index;
-} sp_active_handler_t;
-
-
-class Sql_condition_info : public Sql_alloc
-{
-public:
-  /** SQL error code. */
-  uint m_sql_errno;
-
-  /** Error level. */
-  Sql_condition::enum_warning_level m_level;
-
-  /** SQLSTATE. */
-  char m_sql_state[SQLSTATE_LENGTH + 1];
-
-  /** Text message. */
-  char m_message[MYSQL_ERRMSG_SIZE];
-
-  void set(uint sql_errno, const char* sqlstate,
-           Sql_condition::enum_warning_level level,
-           const char* msg)
-  {
-    m_sql_errno= sql_errno;
-    m_level= level;
-
-    memcpy(m_sql_state, sqlstate, SQLSTATE_LENGTH);
-    m_sql_state[SQLSTATE_LENGTH]= '\0';
-
-    strncpy(m_message, msg, MYSQL_ERRMSG_SIZE);
-  }
-
-  void clear()
-  {
-    m_sql_errno= 0;
-    m_level= Sql_condition::WARN_LEVEL_ERROR;
-
-    m_sql_state[0]= '\0';
-    m_message[0]= '\0';
-  }
-};
 
 
 /*
@@ -119,251 +57,412 @@ public:
 
 class sp_rcontext : public Sql_alloc
 {
-  sp_rcontext(const sp_rcontext &); /* Prevent use of these */
-  void operator=(sp_rcontext &);
-
- public:
-
-  /*
-    Arena used to (re) allocate items on . E.g. reallocate INOUT/OUT
-    SP parameters when they don't fit into prealloced items. This
-    is common situation with String items. It is used mainly in
-    sp_eval_func_item().
-  */
-  Query_arena *callers_arena;
-
-  /*
-    End a open result set before start executing a continue/exit
-    handler if one is found as otherwise the client will hang
-    due to a violation of the client/server protocol.
-  */
-  bool end_partial_result_set;
-
-#ifndef DBUG_OFF
-  /*
-    The routine for which this runtime context is created. Used for checking
-    if correct runtime context is used for variable handling.
-  */
-  sp_head *sp;
-#endif
-
-  sp_rcontext(sp_pcontext *root_parsing_ctx, Field *return_value_fld,
-              sp_rcontext *prev_runtime_ctx);
-  bool init(THD *thd);
+public:
+  /// Construct and properly initialize a new sp_rcontext instance. The static
+  /// create-function is needed because we need a way to return an error from
+  /// the constructor.
+  ///
+  /// @param thd              Thread handle.
+  /// @param root_parsing_ctx Top-level parsing context for this stored program.
+  /// @param return_value_fld Field object to store the return value
+  ///                         (for stored functions only).
+  ///
+  /// @return valid sp_rcontext object or NULL in case of OOM-error.
+  static sp_rcontext *create(THD *thd,
+                             const sp_pcontext *root_parsing_ctx,
+                             Field *return_value_fld);
 
   ~sp_rcontext();
 
-  int
-  set_variable(THD *thd, uint var_idx, Item **value);
-
-  Item *
-  get_item(uint var_idx);
+private:
+  sp_rcontext(const sp_pcontext *root_parsing_ctx,
+              Field *return_value_fld,
+              bool in_sub_stmt);
 
-  Item **
-  get_item_addr(uint var_idx);
+  // Prevent use of copying constructor and operator.
+  sp_rcontext(const sp_rcontext &);
+  void operator=(sp_rcontext &);
 
-  bool
-  set_return_value(THD *thd, Item **return_value_item);
+private:
+  /// This is an auxillary class to store entering instruction pointer for an
+  /// SQL-handler.
+  class sp_handler_entry : public Sql_alloc
+  {
+  public:
+    /// Handler definition (from parsing context).
+    const sp_handler *handler;
+
+    /// Instruction pointer to the first instruction.
+    uint first_ip;
+
+    /// The constructor.
+    ///
+    /// @param _handler   sp_handler object.
+    /// @param _first_ip  first instruction pointer.
+    sp_handler_entry(const sp_handler *_handler, uint _first_ip)
+     :handler(_handler), first_ip(_first_ip)
+    { }
+  };
 
-  inline bool
-  is_return_value_set() const
+public:
+  /// This class stores basic information about SQL-condition, such as:
+  ///   - SQL error code;
+  ///   - error level;
+  ///   - SQLSTATE;
+  ///   - text message.
+  ///
+  /// It's used to organize runtime SQL-handler call stack.
+  ///
+  /// Standard Sql_condition class can not be used, because we don't always have
+  /// an Sql_condition object for an SQL-condition in Diagnostics_area.
+  ///
+  /// Eventually, this class should be moved to sql_error.h, and be a part of
+  /// standard SQL-condition processing (Diagnostics_area should contain an
+  /// object for active SQL-condition, not just information stored in DA's
+  /// fields).
+  class Sql_condition_info : public Sql_alloc
   {
-    return m_return_value_set;
-  }
+  public:
+    /// SQL error code.
+    uint sql_errno;
+
+    /// Error level.
+    Sql_condition::enum_warning_level level;
+
+    /// SQLSTATE.
+    char sql_state[SQLSTATE_LENGTH + 1];
+
+    /// Text message.
+    char *message;
+
+    /// The constructor.
+    ///
+    /// @param _sql_condition  The SQL condition.
+    /// @param arena           Query arena for SP
+    Sql_condition_info(const Sql_condition *_sql_condition,
+                       Query_arena *arena)
+      :sql_errno(_sql_condition->get_sql_errno()),
+       level(_sql_condition->get_level())
+    {
+      memcpy(sql_state, _sql_condition->get_sqlstate(), SQLSTATE_LENGTH);
+      sql_state[SQLSTATE_LENGTH]= '\0';
+
+      message= strdup_root(arena->mem_root, _sql_condition->get_message_text());
+    }
+  };
 
-  /*
-    SQL handlers support.
-  */
+private:
+  /// This class represents a call frame of SQL-handler (one invocation of a
+  /// handler). Basically, it's needed to store continue instruction pointer for
+  /// CONTINUE SQL-handlers.
+  class Handler_call_frame : public Sql_alloc
+  {
+  public:
+    /// SQL-condition, triggered handler activation.
+    const Sql_condition_info *sql_condition;
+
+    /// Continue-instruction-pointer for CONTINUE-handlers.
+    /// The attribute contains 0 for EXIT-handlers.
+    uint continue_ip;
+
+    /// The constructor.
+    ///
+    /// @param _sql_condition SQL-condition, triggered handler activation.
+    /// @param _continue_ip   Continue instruction pointer.
+    Handler_call_frame(const Sql_condition_info *_sql_condition,
+                       uint _continue_ip)
+     :sql_condition(_sql_condition),
+      continue_ip(_continue_ip)
+    { }
+ };
 
-  void push_handler(struct sp_cond_type *cond, uint h, int type);
+public:
+  /// Arena used to (re) allocate items on. E.g. reallocate INOUT/OUT
+  /// SP-variables when they don't fit into prealloced items. This is common
+  /// situation with String items. It is used mainly in sp_eval_func_item().
+  Query_arena *callers_arena;
 
-  void pop_handlers(uint count);
+  /// Flag to end an open result set before start executing an SQL-handler
+  /// (if one is found). Otherwise the client will hang due to a violation
+  /// of the client/server protocol.
+  bool end_partial_result_set;
 
-  bool
-  find_handler(THD *thd,
-               uint sql_errno,
-               const char *sqlstate,
-               Sql_condition::enum_warning_level level,
-               const char *msg);
+#ifndef DBUG_OFF
+  /// The stored program for which this runtime context is created. Used for
+  /// checking if correct runtime context is used for variable handling.
+  sp_head *sp;
+#endif
 
-  Sql_condition_info *raised_condition() const;
+  /////////////////////////////////////////////////////////////////////////
+  // SP-variables.
+  /////////////////////////////////////////////////////////////////////////
 
-  void
-  push_hstack(uint h);
+  int set_variable(THD *thd, uint var_idx, Item **value)
+  { return set_variable(thd, m_var_table->field[var_idx], value); }
 
-  uint
-  pop_hstack();
+  Item *get_item(uint var_idx) const
+  { return m_var_items[var_idx]; }
 
-  bool
-  activate_handler(THD *thd,
-                   uint *ip,
-                   sp_instr *instr,
-                   Query_arena *execute_arena,
-                   Query_arena *backup_arena);
+  Item **get_item_addr(uint var_idx) const
+  { return m_var_items.array() + var_idx; }
 
+  bool set_return_value(THD *thd, Item **return_value_item);
 
-  void
-  exit_handler();
+  bool is_return_value_set() const
+  { return m_return_value_set; }
 
-  void
-  push_cursor(sp_lex_keeper *lex_keeper, sp_instr_cpush *i);
+  /////////////////////////////////////////////////////////////////////////
+  // SQL-handlers.
+  /////////////////////////////////////////////////////////////////////////
 
-  void
-  pop_cursors(uint count);
+  /// Create a new sp_handler_entry instance and push it to the handler call
+  /// stack.
+  ///
+  /// @param handler  SQL-handler object.
+  /// @param first_ip First instruction pointer of the handler.
+  ///
+  /// @return error flag.
+  /// @retval false on success.
+  /// @retval true on error.
+  bool push_handler(sp_handler *handler, uint first_ip);
 
-  inline void
-  pop_all_cursors()
-  {
-    pop_cursors(m_ccount);
-  }
+  /// Pop and delete given number of sp_handler_entry instances from the handler
+  /// call stack.
+  ///
+  /// @param count Number of handler entries to pop & delete.
+  void pop_handlers(int count);
 
-  inline sp_cursor *
-  get_cursor(uint i)
+  const Sql_condition_info *raised_condition() const
   {
-    return m_cstack[i];
+    return m_handler_call_stack.elements() ?
+      (*m_handler_call_stack.back())->sql_condition : NULL;
   }
 
-  /*
-    CASE expressions support.
-  */
+  /// Handle current SQL condition (if any).
+  ///
+  /// This is the public-interface function to handle SQL conditions in
+  /// stored routines.
+  ///
+  /// @param thd            Thread handle.
+  /// @param ip[out]        Instruction pointer to the first handler
+  ///                       instruction.
+  /// @param cur_spi        Current SP instruction.
+  ///
+  /// @retval true if an SQL-handler has been activated. That means, all of
+  /// the following conditions are satisfied:
+  ///   - the SP-instruction raised SQL-condition(s),
+  ///   - and there is an SQL-handler to process at least one of those
+  ///     SQL-conditions,
+  ///   - and that SQL-handler has been activated.
+  /// Note, that the return value has nothing to do with "error flag"
+  /// semantics.
+  ///
+  /// @retval false otherwise.
+  bool handle_sql_condition(THD *thd,
+                            uint *ip,
+                            const sp_instr *cur_spi);
+
+  /// Remove latest call frame from the handler call stack.
+  ///
+  /// @param da Diagnostics area containing handled conditions.
+  ///
+  /// @return continue instruction pointer of the removed handler.
+  uint exit_handler(Diagnostics_area *da);
+
+  /////////////////////////////////////////////////////////////////////////
+  // Cursors.
+  /////////////////////////////////////////////////////////////////////////
+
+  /// Create a new sp_cursor instance and push it to the cursor stack.
+  ///
+  /// @param lex_keeper SP-instruction execution helper.
+  /// @param i          Cursor-push instruction.
+  ///
+  /// @return error flag.
+  /// @retval false on success.
+  /// @retval true on error.
+  bool push_cursor(sp_lex_keeper *lex_keeper, sp_instr_cpush *i);
+
+  /// Pop and delete given number of sp_cursor instance from the cursor stack.
+  ///
+  /// @param count Number of cursors to pop & delete.
+  void pop_cursors(uint count);
+
+  void pop_all_cursors()
+  { pop_cursors(m_ccount); }
+
+  sp_cursor *get_cursor(uint i) const
+  { return m_cstack[i]; }
+
+  /////////////////////////////////////////////////////////////////////////
+  // CASE expressions.
+  /////////////////////////////////////////////////////////////////////////
+
+  /// Set CASE expression to the specified value.
+  ///
+  /// @param thd             Thread handler.
+  /// @param case_expr_id    The CASE expression identifier.
+  /// @param case_expr_item  The CASE expression value
+  ///
+  /// @return error flag.
+  /// @retval false on success.
+  /// @retval true on error.
+  ///
+  /// @note The idea is to reuse Item_cache for the expression of the one
+  /// CASE statement. This optimization takes place when there is CASE
+  /// statement inside of a loop. So, in other words, we will use the same
+  /// object on each iteration instead of creating a new one for each
+  /// iteration.
+  ///
+  /// TODO
+  ///   Hypothetically, a type of CASE expression can be different for each
+  ///   iteration. For instance, this can happen if the expression contains
+  ///   a session variable (something like @@VAR) and its type is changed
+  ///   from one iteration to another.
+  ///
+  ///   In order to cope with this problem, we check type each time, when we
+  ///   use already created object. If the type does not match, we re-create
+  ///   Item.  This also can (should?) be optimized.
+  bool set_case_expr(THD *thd, int case_expr_id, Item **case_expr_item_ptr);
+
+  Item *get_case_expr(int case_expr_id) const
+  { return m_case_expr_holders[case_expr_id]; }
+
+  Item ** get_case_expr_addr(int case_expr_id) const
+  { return (Item**) m_case_expr_holders.array() + case_expr_id; }
 
-  int
-  set_case_expr(THD *thd, int case_expr_id, Item **case_expr_item_ptr);
+private:
+  /// Internal function to allocate memory for arrays.
+  ///
+  /// @param thd Thread handle.
+  ///
+  /// @return error flag: false on success, true in case of failure.
+  bool alloc_arrays(THD *thd);
+
+  /// Create and initialize a table to store SP-variables.
+  ///
+  /// param thd Thread handle.
+  ///
+  /// @return error flag.
+  /// @retval false on success.
+  /// @retval true on error.
+  bool init_var_table(THD *thd);
 
-  Item *
-  get_case_expr(int case_expr_id);
+  /// Create and initialize an Item-adapter (Item_field) for each SP-var field.
+  ///
+  /// param thd Thread handle.
+  ///
+  /// @return error flag.
+  /// @retval false on success.
+  /// @retval true on error.
+  bool init_var_items(THD *thd);
+
+  /// Create an instance of appropriate Item_cache class depending on the
+  /// specified type in the callers arena.
+  ///
+  /// @note We should create cache items in the callers arena, as they are
+  /// used between in several instructions.
+  ///
+  /// @param thd   Thread handler.
+  /// @param item  Item to get the expression type.
+  ///
+  /// @return Pointer to valid object on success, or NULL in case of error.
+  Item_cache *create_case_expr_holder(THD *thd, const Item *item) const;
 
-  Item **
-  get_case_expr_addr(int case_expr_id);
+  int set_variable(THD *thd, Field *field, Item **value);
 
 private:
-  sp_pcontext *m_root_parsing_ctx;
+  /// Top-level (root) parsing context for this runtime context.
+  const sp_pcontext *m_root_parsing_ctx;
 
-  /* Virtual table for storing variables. */
+  /// Virtual table for storing SP-variables.
   TABLE *m_var_table;
 
-  /*
-    Collection of Item_field proxies, each of them points to the corresponding
-    field in m_var_table.
-  */
-  Item **m_var_items;
+  /// Collection of Item_field proxies, each of them points to the
+  /// corresponding field in m_var_table.
+  Bounds_checked_array<Item *> m_var_items;
 
-  /*
-    This is a pointer to a field, which should contain return value for stored
-    functions (only). For stored procedures, this pointer is NULL.
-  */
+  /// This is a pointer to a field, which should contain return value for
+  /// stored functions (only). For stored procedures, this pointer is NULL.
   Field *m_return_value_fld;
 
-  /*
-    Indicates whether the return value (in m_return_value_fld) has been set
-    during execution.
-  */
+  /// Indicates whether the return value (in m_return_value_fld) has been
+  /// set during execution.
   bool m_return_value_set;
 
-  /**
-    TRUE if the context is created for a sub-statement.
-  */
-  bool in_sub_stmt;
+  /// Flag to tell if the runtime context is created for a sub-statement.
+  bool m_in_sub_stmt;
 
-  sp_handler_t *m_handler;      // Visible handlers
+  /// Stack of visible handlers.
+  Dynamic_array<sp_handler_entry *> m_handlers;
 
-  /**
-    SQL conditions caught by each handler.
-    This is an array indexed by handler index.
-  */
-  Sql_condition_info *m_raised_conditions;
+  /// Stack of caught SQL conditions.
+  Dynamic_array<Handler_call_frame *> m_handler_call_stack;
 
-  uint m_hcount;                // Stack pointer for m_handler
-  uint *m_hstack;               // Return stack for continue handlers
-  uint m_hsp;                   // Stack pointer for m_hstack
-  /** Active handler stack. */
-  sp_active_handler_t *m_in_handler;
-  uint m_ihsp;                  // Stack pointer for m_in_handler
-  int m_hfound;                 // Set by find_handler; -1 if not found
+  /// Stack of cursors.
+  Bounds_checked_array<sp_cursor *> m_cstack;
 
-  sp_cursor **m_cstack;
+  /// Current number of cursors in m_cstack.
   uint m_ccount;
 
-  Item_cache **m_case_expr_holders;
-
-  /* Previous runtime context (NULL if none) */
-  sp_rcontext *m_prev_runtime_ctx;
-
-private:
-  bool init_var_table(THD *thd);
-  bool init_var_items();
-
-  Item_cache *create_case_expr_holder(THD *thd, const Item *item);
-
-  int set_variable(THD *thd, Field *field, Item **value);
+  /// Array of CASE expression holders.
+  Bounds_checked_array<Item_cache *> m_case_expr_holders;
 }; // class sp_rcontext : public Sql_alloc
 
+///////////////////////////////////////////////////////////////////////////
+// sp_cursor declaration.
+///////////////////////////////////////////////////////////////////////////
 
-/*
-  An interceptor of cursor result set used to implement
-  FETCH <cname> INTO <varlist>.
-*/
-
-class Select_fetch_into_spvars: public select_result_interceptor
-{
-  List<struct sp_variable> *spvar_list;
-  uint field_count;
-public:
-  Select_fetch_into_spvars() {}               /* Remove gcc warning */
-  uint get_field_count() { return field_count; }
-  void set_spvar_list(List<struct sp_variable> *vars) { spvar_list= vars; }
-
-  virtual bool send_eof() { return FALSE; }
-  virtual int send_data(List<Item> &items);
-  virtual int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
-};
-
+class Server_side_cursor;
+typedef class st_select_lex_unit SELECT_LEX_UNIT;
 
 /* A mediator between stored procedures and server side cursors */
 
 class sp_cursor : public Sql_alloc
 {
-public:
+private:
+  /// An interceptor of cursor result set used to implement
+  /// FETCH <cname> INTO <varlist>.
+  class Select_fetch_into_spvars: public select_result_interceptor
+  {
+    List<sp_variable> *spvar_list;
+    uint field_count;
+  public:
+    Select_fetch_into_spvars() {}               /* Remove gcc warning */
+    uint get_field_count() { return field_count; }
+    void set_spvar_list(List<sp_variable> *vars) { spvar_list= vars; }
+
+    virtual bool send_eof() { return FALSE; }
+    virtual bool send_data(List<Item> &items);
+    virtual int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
+};
 
+public:
   sp_cursor(sp_lex_keeper *lex_keeper, sp_instr_cpush *i);
 
   virtual ~sp_cursor()
-  {
-    destroy();
-  }
+  { destroy(); }
 
-  sp_lex_keeper *
-  get_lex_keeper() { return m_lex_keeper; }
+  sp_lex_keeper *get_lex_keeper() { return m_lex_keeper; }
 
-  int
-  open(THD *thd);
+  int open(THD *thd);
 
-  int
-  close(THD *thd);
+  int close(THD *thd);
 
-  inline bool
-  is_open()
-  {
-    return test(server_side_cursor);
-  }
+  my_bool is_open()
+  { return test(server_side_cursor); }
 
-  int
-  fetch(THD *, List<struct sp_variable> *vars);
+  int fetch(THD *, List<sp_variable> *vars);
 
-  inline sp_instr_cpush *
-  get_instr()
-  {
-    return m_i;
-  }
+  sp_instr_cpush *get_instr()
+  { return m_i; }
 
 private:
-
   Select_fetch_into_spvars result;
   sp_lex_keeper *m_lex_keeper;
   Server_side_cursor *server_side_cursor;
   sp_instr_cpush *m_i;		// My push instruction
-  void
-  destroy();
+  void destroy();
 
 }; // class sp_cursor : public Sql_alloc