creating mysql helper library for the various mysql backends

2 files changed, 681 insertions, 0 deletions

diff --git a/src/mysql/Makefile.am b/src/mysql/Makefile.am
new file mode 100644
index 000000000..1711e7572
--- /dev/null
+++ b/src/mysql/Makefile.am
@@ -0,0 +1,20 @@
+INCLUDES = -I$(top_srcdir)/src/include
+
+if MINGW
+  WINFLAGS = -Wl,--no-undefined -Wl,--export-all-symbols
+endif
+
+if USE_COVERAGE
+  AM_CFLAGS = --coverage
+endif
+
+lib_LTLIBRARIES = libgnunetmysql.la
+
+libgnunetmysql_la_SOURCES = \
+  mysql.c
+libgnunetmysql_la_LIBADD = -lmysqlclient \
+ $(top_builddir)/src/util/libgnunetutil.la  
+libgnunetmysql_la_LDFLAGS = \
+ $(GN_LIB_LDFLAGS) \
+  -version-info 0:0:0
+
diff --git a/src/mysql/mysql.c b/src/mysql/mysql.c
new file mode 100644
index 000000000..0fc98308c
--- /dev/null
+++ b/src/mysql/mysql.c
@@ -0,0 +1,661 @@
+/*
+     This file is part of GNUnet
+     (C) 2012 Christian Grothoff (and other contributing authors)
+
+     GNUnet 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; either version 3, or (at your
+     option) any later version.
+
+     GNUnet 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 GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+/**
+ * @file mysql/mysql.c
+ * @brief library to help with access to a MySQL database
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <mysql/mysql.h>
+#include "gnunet_mysql_lib.h"
+
+/**
+ * Maximum number of supported parameters for a prepared
+ * statement.  Increase if needed.
+ */
+#define MAX_PARAM 16
+
+
+/**
+ * Die with an error message that indicates
+ * a failure of the command 'cmd' with the message given
+ * by strerror(errno).
+ */
+#define DIE_MYSQL(cmd, dbh) do { GNUNET_log_from (GNUNET_ERROR_TYPE__ERROR, "mysql", _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, mysql_error((dbh)->dbf)); GNUNET_abort(); } while(0);
+
+/**
+ * Log an error message at log-level 'level' that indicates
+ * a failure of the command 'cmd' on file 'filename'
+ * with the message given by strerror(errno).
+ */
+#define LOG_MYSQL(level, cmd, dbh) do { GNUNET_log_from (level, "mysql", _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, mysql_error((dbh)->dbf)); } while(0);
+
+
+/**
+ * Mysql context.
+ */
+struct GNUNET_MYSQL_Context
+{
+  
+  /**
+   * Our configuration.
+   */
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+  
+  /**
+   * Our section.
+   */
+  const char *section;
+
+  /**
+   * Handle to the mysql database.
+   */
+  MYSQL *dbf;
+
+  /**
+   * Head of list of our prepared statements.
+   */
+  struct GNUNET_MYSQL_StatementHandle *shead;
+
+  /**
+   * Tail of list of our prepared statements.
+   */
+  struct GNUNET_MYSQL_StatementHandle *stail;
+
+  /**
+   * Filename of "my.cnf" (msyql configuration).
+   */
+  char *cnffile;
+
+};
+
+
+/**
+ * Handle for a prepared statement.
+ */
+struct GNUNET_MYSQL_StatementHandle
+{
+
+  /**
+   * Kept in a DLL.
+   */
+  struct GNUNET_MYSQL_StatementHandle *next;
+
+  /**
+   * Kept in a DLL.
+   */
+  struct GNUNET_MYSQL_StatementHandle *prev;
+
+  /**
+   * Original query string.
+   */
+  char *query;
+
+  /**
+   * Handle to MySQL prepared statement.
+   */
+  MYSQL_STMT *statement;
+
+  /**
+   * Is the MySQL prepared statement valid, or do we need to re-initialize it?
+   */
+  int valid;
+
+};
+
+
+/**
+ * Obtain the location of ".my.cnf".
+ *
+ * @param cfg our configuration
+ * @return NULL on error
+ */
+static char *
+get_my_cnf_path (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                 const char *section)
+{
+  char *cnffile;
+  char *home_dir;
+  struct stat st;
+
+#ifndef WINDOWS
+  struct passwd *pw;
+#endif
+  int configured;
+
+#ifndef WINDOWS
+  pw = getpwuid (getuid ());
+  if (!pw)
+  {
+    GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_ERROR, "mysql", "getpwuid");
+    return NULL;
+  }
+  if (GNUNET_YES ==
+      GNUNET_CONFIGURATION_have_value (cfg, section, "CONFIG"))
+  {
+    GNUNET_assert (GNUNET_OK ==
+                   GNUNET_CONFIGURATION_get_value_filename (cfg,
+                                                            section,
+                                                            "CONFIG",
+                                                            &cnffile));
+    configured = GNUNET_YES;
+  }
+  else
+  {
+    home_dir = GNUNET_strdup (pw->pw_dir);
+    GNUNET_asprintf (&cnffile, "%s/.my.cnf", home_dir);
+    GNUNET_free (home_dir);
+    configured = GNUNET_NO;
+  }
+#else
+  home_dir = (char *) GNUNET_malloc (_MAX_PATH + 1);
+  plibc_conv_to_win_path ("~/", home_dir);
+  GNUNET_asprintf (&cnffile, "%s/.my.cnf", home_dir);
+  GNUNET_free (home_dir);
+  configured = GNUNET_NO;
+#endif
+  GNUNET_log_from (GNUNET_ERROR_TYPE_INFO,
+                   "mysql",
+                   _("Trying to use file `%s' for MySQL configuration.\n"), cnffile);
+  if ((0 != STAT (cnffile, &st)) || (0 != ACCESS (cnffile, R_OK)) ||
+      (!S_ISREG (st.st_mode)))
+  {
+    if (configured == GNUNET_YES)
+      GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                       "mysql",
+                       _("Could not access file `%s': %s\n"), cnffile,
+                       STRERROR (errno));
+    GNUNET_free (cnffile);
+    return NULL;
+  }
+  return cnffile;
+}
+
+
+/**
+ * Open the connection with the database (and initialize
+ * our default options).
+ *
+ * @param mc database context to initialze
+ * @return GNUNET_OK on success
+ */
+static int
+iopen (struct GNUNET_MYSQL_Context *mc)
+{
+  char *mysql_dbname;
+  char *mysql_server;
+  char *mysql_user;
+  char *mysql_password;
+  unsigned long long mysql_port;
+  my_bool reconnect;
+  unsigned int timeout;
+
+  mc->dbf = mysql_init (NULL);
+  if (mc->dbf == NULL)
+    return GNUNET_SYSERR;
+  if (mc->cnffile != NULL)
+    mysql_options (mc->dbf, MYSQL_READ_DEFAULT_FILE, mc->cnffile);
+  mysql_options (mc->dbf, MYSQL_READ_DEFAULT_GROUP, "client");
+  reconnect = 0;
+  mysql_options (mc->dbf, MYSQL_OPT_RECONNECT, &reconnect);
+  mysql_options (mc->dbf, MYSQL_OPT_CONNECT_TIMEOUT, (const void *) &timeout);
+  mysql_options (mc->dbf, MYSQL_SET_CHARSET_NAME, "UTF8");
+  timeout = 60;                 /* in seconds */
+  mysql_options (mc->dbf, MYSQL_OPT_READ_TIMEOUT, (const void *) &timeout);
+  mysql_options (mc->dbf, MYSQL_OPT_WRITE_TIMEOUT, (const void *) &timeout);
+  mysql_dbname = NULL;
+  if (GNUNET_YES ==
+      GNUNET_CONFIGURATION_have_value (mc->cfg, mc->section,
+                                       "DATABASE"))
+    GNUNET_assert (GNUNET_OK ==
+                   GNUNET_CONFIGURATION_get_value_string (mc->cfg,
+                                                          mc->section,
+                                                          "DATABASE",
+                                                          &mysql_dbname));
+  else
+    mysql_dbname = GNUNET_strdup ("gnunet");
+  mysql_user = NULL;
+  if (GNUNET_YES ==
+      GNUNET_CONFIGURATION_have_value (mc->cfg, mc->section,
+                                       "USER"))
+  {
+    GNUNET_assert (GNUNET_OK ==
+                   GNUNET_CONFIGURATION_get_value_string (mc->cfg,
+                                                          mc->section,
+                                                          "USER", &mysql_user));
+  }
+  mysql_password = NULL;
+  if (GNUNET_YES ==
+      GNUNET_CONFIGURATION_have_value (mc->cfg, mc->section,
+                                       "PASSWORD"))
+  {
+    GNUNET_assert (GNUNET_OK ==
+                   GNUNET_CONFIGURATION_get_value_string (mc->cfg,
+                                                          mc->section,
+                                                          "PASSWORD",
+                                                          &mysql_password));
+  }
+  mysql_server = NULL;
+  if (GNUNET_YES ==
+      GNUNET_CONFIGURATION_have_value (mc->cfg, mc->section,
+                                       "HOST"))
+  {
+    GNUNET_assert (GNUNET_OK ==
+                   GNUNET_CONFIGURATION_get_value_string (mc->cfg,
+                                                          mc->section,
+                                                          "HOST",
+                                                          &mysql_server));
+  }
+  mysql_port = 0;
+  if (GNUNET_YES ==
+      GNUNET_CONFIGURATION_have_value (mc->cfg, mc->section,
+                                       "PORT"))
+  {
+    GNUNET_assert (GNUNET_OK ==
+                   GNUNET_CONFIGURATION_get_value_number (mc->cfg,
+                                                          mc->section,
+                                                          "PORT", &mysql_port));
+  }
+
+  GNUNET_assert (mysql_dbname != NULL);
+  mysql_real_connect (mc->dbf, mysql_server, mysql_user, mysql_password,
+                      mysql_dbname, (unsigned int) mysql_port, NULL,
+                      CLIENT_IGNORE_SIGPIPE);
+  GNUNET_free_non_null (mysql_server);
+  GNUNET_free_non_null (mysql_user);
+  GNUNET_free_non_null (mysql_password);
+  GNUNET_free (mysql_dbname);
+  if (mysql_error (mc->dbf)[0])
+  {
+    LOG_MYSQL (GNUNET_ERROR_TYPE_ERROR, "mysql_real_connect", mc);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Create a mysql context.
+ *
+ * @param cfg configuration
+ * @param section configuration section to use to get MySQL configuration options
+ * @return the mysql context
+ */
+struct GNUNET_MYSQL_Context *
+GNUNET_MYSQL_context_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
+                             const char *section)
+{
+  struct GNUNET_MYSQL_Context *mc;
+
+  mc = GNUNET_malloc (sizeof (struct GNUNET_MYSQL_Context));
+  mc->cfg = cfg;
+  mc->section = section;
+  mc->cnffile = get_my_cnf_path (cfg, section);
+  
+  return mc;
+}
+
+
+/**
+ * Close database connection and all prepared statements (we got a DB
+ * disconnect error).
+ *
+ * @param mc mysql context
+ */
+static void
+iclose (struct GNUNET_MYSQL_Context *mc)
+{
+  struct GNUNET_MYSQL_StatementHandle *sh;
+
+  for (sh = mc->shead; NULL != sh; sh = sh->next)
+  {
+    if (GNUNET_YES == sh->valid)
+    {
+      mysql_stmt_close (sh->statement);
+      sh->valid = GNUNET_NO;
+    }
+    sh->statement = NULL;
+  }
+  if (NULL != mc->dbf)
+  {
+    mysql_close (mc->dbf);
+    mc->dbf = NULL;
+  }
+}
+
+
+/**
+ * Destroy a mysql context.  Also frees all associated prepared statements.
+ * 
+ * @param mc context to destroy
+ */
+void
+GNUNET_MYSQL_context_destroy (struct GNUNET_MYSQL_Context *mc)
+{
+  struct GNUNET_MYSQL_StatementHandle *sh;
+
+  iclose (mc);
+  while (NULL != (sh = mc->shead))
+  {
+    GNUNET_CONTAINER_DLL_remove (mc->shead, mc->stail, sh);
+    GNUNET_free (sh->query);
+    GNUNET_free (sh);
+  }
+  GNUNET_free (mc);
+}
+
+
+/**
+ * Prepare a statement.  Prepared statements are automatically discarded
+ * when the MySQL context is destroyed.
+ *
+ * @param mc mysql context
+ * @param query query text
+ * @return prepared statement, NULL on error
+ */
+struct GNUNET_MYSQL_StatementHandle *
+GNUNET_MYSQL_statement_prepare (struct GNUNET_MYSQL_Context *mc,
+                                const char *query)
+{
+  struct GNUNET_MYSQL_StatementHandle *sh;
+
+  sh = GNUNET_malloc (sizeof (struct GNUNET_MYSQL_StatementHandle));
+  sh->query = GNUNET_strdup (query);
+  GNUNET_CONTAINER_DLL_insert (mc->shead, mc->stail, sh);
+  return sh;
+}
+
+
+/**
+ * Run a SQL statement.
+ *
+ * @param mc mysql context
+ * @param sql SQL statement to run
+ * @return GNUNET_OK on success
+ *         GNUNET_SYSERR if there was a problem
+ */
+int
+GNUNET_MYSQL_statement_run (struct GNUNET_MYSQL_Context *mc,
+                            const char *sql)
+{
+  if ((NULL == mc->dbf) && (GNUNET_OK != iopen (mc)))
+    return GNUNET_SYSERR;
+  mysql_query (mc->dbf, sql);
+  if (mysql_error (mc->dbf)[0])
+  {
+    LOG_MYSQL (GNUNET_ERROR_TYPE_ERROR, "mysql_query", mc);
+    iclose (mc);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Prepare a statement for running.
+ *
+ * @param mc mysql context
+ * @param sh statement handle to prepare
+ * @return GNUNET_OK on success
+ */
+static int
+prepare_statement (struct GNUNET_MYSQL_Context *mc,
+                   struct GNUNET_MYSQL_StatementHandle *sh)
+{
+  if (GNUNET_YES == sh->valid)
+    return GNUNET_OK;
+  if ((NULL == mc->dbf) && (GNUNET_OK != iopen (mc)))
+    return GNUNET_SYSERR;
+  sh->statement = mysql_stmt_init (mc->dbf);
+  if (NULL == sh->statement)
+  {
+    iclose (mc);
+    return GNUNET_SYSERR;
+  }
+  if (0 != mysql_stmt_prepare (sh->statement, sh->query, strlen (sh->query)))
+  {
+    LOG_MYSQL (GNUNET_ERROR_TYPE_ERROR, "mysql_stmt_prepare", mc);
+    mysql_stmt_close (sh->statement);
+    sh->statement = NULL;
+    iclose (mc);
+    return GNUNET_SYSERR;
+  }
+  sh->valid = GNUNET_YES;
+  return GNUNET_OK;
+}
+
+
+/**
+ * Bind the parameters for the given MySQL statement
+ * and run it.
+ *
+ * @param mc mysql context
+ * @param sh statement to bind and run
+ * @param ap arguments for the binding
+ * @return GNUNET_SYSERR on error, GNUNET_OK on success
+ */
+static int
+init_params (struct GNUNET_MYSQL_Context *mc, 
+             struct GNUNET_MYSQL_StatementHandle *sh,
+             va_list ap)
+{
+  MYSQL_BIND qbind[MAX_PARAM];
+  unsigned int pc;
+  unsigned int off;
+  enum enum_field_types ft;
+
+  pc = mysql_stmt_param_count (sh->statement);
+  if (pc > MAX_PARAM)
+  {
+    /* increase internal constant! */
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  memset (qbind, 0, sizeof (qbind));
+  off = 0;
+  ft = 0;
+  while ((pc > 0) && (-1 != (int) (ft = va_arg (ap, enum enum_field_types))))
+  {
+    qbind[off].buffer_type = ft;
+    switch (ft)
+    {
+    case MYSQL_TYPE_FLOAT:
+      qbind[off].buffer = va_arg (ap, float *);
+
+      break;
+    case MYSQL_TYPE_LONGLONG:
+      qbind[off].buffer = va_arg (ap, unsigned long long *);
+      qbind[off].is_unsigned = va_arg (ap, int);
+
+      break;
+    case MYSQL_TYPE_LONG:
+      qbind[off].buffer = va_arg (ap, unsigned int *);
+      qbind[off].is_unsigned = va_arg (ap, int);
+
+      break;
+    case MYSQL_TYPE_VAR_STRING:
+    case MYSQL_TYPE_STRING:
+    case MYSQL_TYPE_BLOB:
+      qbind[off].buffer = va_arg (ap, void *);
+      qbind[off].buffer_length = va_arg (ap, unsigned long);
+      qbind[off].length = va_arg (ap, unsigned long *);
+
+      break;
+    default:
+      /* unsupported type */
+      GNUNET_break (0);
+      return GNUNET_SYSERR;
+    }
+    pc--;
+    off++;
+  }
+  if (!((pc == 0) && (-1 != (int) ft) && (va_arg (ap, int) == -1)))
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  if (mysql_stmt_bind_param (sh->statement, qbind))
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                     "mysql",
+                     _("`%s' failed at %s:%d with error: %s\n"),
+                     "mysql_stmt_bind_param", __FILE__, __LINE__,
+                     mysql_stmt_error (sh->statement));
+    iclose (mc);
+    return GNUNET_SYSERR;
+  }
+  if (mysql_stmt_execute (sh->statement))
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                     "mysql",
+                     _("`%s' failed at %s:%d with error: %s\n"),
+                     "mysql_stmt_execute", __FILE__, __LINE__,
+                     mysql_stmt_error (sh->statement));
+    iclose (mc);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Run a prepared SELECT statement.
+ *
+ * @param mc mysql context
+ * @param sh handle to SELECT statment
+ * @param result_size number of elements in results array
+ * @param results pointer to already initialized MYSQL_BIND
+ *        array (of sufficient size) for passing results
+ * @param processor function to call on each result
+ * @param processor_cls extra argument to processor
+ * @param ... pairs and triplets of "MYSQL_TYPE_XXX" keys and their respective
+ *        values (size + buffer-reference for pointers); terminated
+ *        with "-1"
+ * @return GNUNET_SYSERR on error, otherwise
+ *         the number of successfully affected (or queried) rows
+ */
+int
+GNUNET_MYSQL_statement_run_prepared_select (struct GNUNET_MYSQL_Context *mc,
+                                            struct GNUNET_MYSQL_StatementHandle *sh,
+                                            unsigned int result_size, MYSQL_BIND * results,
+                                            GNUNET_MYSQL_DataProcessor processor,
+                                            void *processor_cls, ...)
+{
+  va_list ap;
+  int ret;
+  unsigned int rsize;
+  int total;
+
+  if (GNUNET_OK != prepare_statement (mc, sh))
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  va_start (ap, processor_cls);
+  if (GNUNET_OK != init_params (mc, sh, ap))
+  {
+    GNUNET_break (0);
+    va_end (ap);
+    return GNUNET_SYSERR;
+  }
+  va_end (ap);
+  rsize = mysql_stmt_field_count (sh->statement);
+  if (rsize > result_size)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  if (mysql_stmt_bind_result (sh->statement, results))
+  {
+    GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                     "mysql",
+                     _("`%s' failed at %s:%d with error: %s\n"),
+                     "mysql_stmt_bind_result", __FILE__, __LINE__,
+                     mysql_stmt_error (sh->statement));
+    iclose (mc);
+    return GNUNET_SYSERR;
+  }
+
+  total = 0;
+  while (1)
+  {
+    ret = mysql_stmt_fetch (sh->statement);
+    if (ret == MYSQL_NO_DATA)
+      break;
+    if (ret != 0)
+    {
+      GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR,
+                       "mysql",
+                       _("`%s' failed at %s:%d with error: %s\n"),
+                       "mysql_stmt_fetch", __FILE__, __LINE__,
+                       mysql_stmt_error (sh->statement));
+      iclose (mc);
+      return GNUNET_SYSERR;
+    }
+    if (processor != NULL)
+      if (GNUNET_OK != processor (processor_cls, rsize, results))
+        break;
+    total++;
+  }
+  mysql_stmt_reset (sh->statement);
+  return total;
+}
+
+
+/**
+ * Run a prepared statement that does NOT produce results.
+ *
+ * @param mc mysql context
+ * @param sh handle to statment
+ * @param insert_id NULL or address where to store the row ID of whatever
+ *        was inserted (only for INSERT statements!)
+ * @param ... pairs and triplets of "MYSQL_TYPE_XXX" keys and their respective
+ *        values (size + buffer-reference for pointers); terminated
+ *        with "-1"
+ * @return GNUNET_SYSERR on error, otherwise
+ *         the number of successfully affected rows
+ */
+int
+GNUNET_MYSQL_statement_run_prepared (struct GNUNET_MYSQL_Context *mc,
+                                     struct GNUNET_MYSQL_StatementHandle *sh,
+                                     unsigned long long *insert_id, ...)
+{
+  va_list ap;
+  int affected;
+
+  if (GNUNET_OK != prepare_statement (mc, sh))
+    return GNUNET_SYSERR;
+  va_start (ap, insert_id);
+  if (GNUNET_OK != init_params (mc, sh, ap))
+  {
+    va_end (ap);
+    return GNUNET_SYSERR;
+  }
+  va_end (ap);
+  affected = mysql_stmt_affected_rows (sh->statement);
+  if (NULL != insert_id)
+    *insert_id = (unsigned long long) mysql_stmt_insert_id (sh->statement);
+  mysql_stmt_reset (sh->statement);
+  return affected;
+}
+
+
+/* end of mysql.c */
+