Merge branch 'firebird-errors'

Improve Firebird errors generation too.

See #1242.

include/soci/firebird/soci-firebird.h

@@ -30,27 +30,16 @@
 namespace soci
 {
 
-std::size_t const stat_size = 20;
-
-// size of buffer for error messages. All examples use this value.
-// Anyone knows, where it is stated that 512 bytes is enough ?
-std::size_t const SOCI_FIREBIRD_ERRMSG = 512;
-
 class SOCI_FIREBIRD_DECL firebird_soci_error : public soci_error
 {
 public:
     firebird_soci_error(std::string const & msg,
         ISC_STATUS const * status = 0);
 
-    ~firebird_soci_error() noexcept override {};
+    error_category get_error_category() const override;
 
     std::string get_backend_name() const override { return "firebird"; }
-    int get_backend_error_code() const override
-    {
-        // We can't return the full vector using this generic interface, so
-        // return just the first status.
-        return status_.empty() ? 0 : status_[0];
-    }
+    int get_backend_error_code() const override;
 
     std::vector<ISC_STATUS> status_;
 };

src/backends/firebird/error-firebird.cpp

@@ -21,13 +21,87 @@ firebird_soci_error::firebird_soci_error(std::string const & msg, ISC_STATUS con
     if (status != 0)
     {
         std::size_t i = 0;
-        while (i < stat_size && status[i] != 0)
+        while (i < ISC_STATUS_LENGTH && status[i] != isc_arg_end)
         {
             status_.push_back(status[i++]);
         }
     }
 }
 
+int firebird_soci_error::get_backend_error_code() const
+{
+    // Search for the InterBase error code in the status vector, which consists
+    // of clusters of 2 (mostly) or 3 (exceptionally, see below) elements.
+    for (std::size_t i = 0; i < status_.size(); i += 2)
+    {
+        switch (status_[i])
+        {
+            case isc_arg_end:
+                // This is never supposed to happen due to the way status_ is
+                // filled in the ctor above.
+                return 0;
+
+            case isc_arg_gds:
+                // Cluster starting with this value contains the error code
+                // we're looking for in the next element.
+                if (i + 1 < status_.size())
+                {
+                    return static_cast<int>(status_[i + 1]);
+                }
+                break;
+
+            case isc_arg_cstring:
+                // This is the only cluster consisting of 3 elements, so skip
+                // an extra one.
+                ++i;
+                break;
+        }
+    }
+
+    return 0;
+}
+
+soci_error::error_category firebird_soci_error::get_error_category() const
+{
+    switch (get_backend_error_code())
+    {
+        case isc_bad_db_format:
+        case isc_unavailable:
+        case isc_wrong_ods:
+        case isc_badodsver:
+        case isc_connect_reject:
+        case isc_login:
+        case isc_network_error:
+        case isc_net_connect_err:
+        case isc_lost_db_connection:
+            return connection_error;
+
+        case isc_syntaxerr:
+        case isc_dsql_error:
+        case isc_command_end_err:
+            return invalid_statement;
+
+        case isc_no_priv:
+            return no_privilege;
+
+        case isc_not_valid:
+        case isc_no_dup:
+        case isc_foreign_key:
+        case isc_primary_key_ref:
+        case isc_primary_key_notnull:
+            return constraint_violation;
+
+        case isc_tra_state:
+            return unknown_transaction_state;
+
+        case isc_io_error:
+        case isc_virmemexh:
+            return system_error;
+    }
+
+    return unknown;
+}
+
 namespace details
 {
 
@@ -36,6 +110,9 @@ namespace firebird
 
 void get_iscerror_details(ISC_STATUS * status_vector, std::string &msg)
 {
+    // Size of buffer for error messages: 4K should be enough for everybody.
+    constexpr std::size_t const SOCI_FIREBIRD_ERRMSG = 4096;
+
     char msg_buffer[SOCI_FIREBIRD_ERRMSG];
     const ISC_STATUS *pvector = status_vector;
 

src/backends/firebird/session.cpp

@@ -42,7 +42,7 @@ firebird_session_backend::firebird_session_backend(
     auto params = parameters;
     params.extract_options_from_space_separated_string();
 
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
     std::string param;
 
     // preparing connection options
@@ -91,7 +91,7 @@ void firebird_session_backend::begin()
 {
     if (trhp_ == 0)
     {
-        ISC_STATUS stat[stat_size];
+        ISC_STATUS stat[ISC_STATUS_LENGTH];
         if (isc_start_transaction(stat, &trhp_, 1, &dbhp_, 0, NULL))
         {
             throw_iscerror(stat);
@@ -106,7 +106,7 @@ firebird_session_backend::~firebird_session_backend()
 
 bool firebird_session_backend::is_connected()
 {
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
     ISC_SCHAR req[] = { isc_info_ods_version, isc_info_end };
     ISC_SCHAR res[256];
 
@@ -115,7 +115,7 @@ bool firebird_session_backend::is_connected()
 
 void firebird_session_backend::commit()
 {
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
 
     if (trhp_ != 0)
     {
@@ -130,7 +130,7 @@ void firebird_session_backend::commit()
 
 void firebird_session_backend::rollback()
 {
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
 
     if (trhp_ != 0)
     {
@@ -153,7 +153,7 @@ isc_tr_handle* firebird_session_backend::current_transaction()
 
 void firebird_session_backend::cleanUp()
 {
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
 
     // at the end of session our transaction is finally commited.
     if (trhp_ != 0)

src/backends/firebird/statement.cpp

@@ -40,7 +40,7 @@ void firebird_statement_backend::prepareSQLDA(XSQLDA ** sqldap, short size)
 
 void firebird_statement_backend::alloc()
 {
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
 
     if (isc_dsql_allocate_statement(stat, &session_.dbhp_, &stmtp_))
     {
@@ -52,7 +52,7 @@ void firebird_statement_backend::clean_up()
 {
     rowsAffectedBulk_ = -1LL;
 
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
 
     if (stmtp_ != 0)
     {
@@ -155,7 +155,7 @@ namespace
         char type_item[] = {isc_info_sql_stmt_type};
         char res_buffer[8];
 
-        ISC_STATUS stat[stat_size];
+        ISC_STATUS stat[ISC_STATUS_LENGTH];
 
         if (isc_dsql_sql_info(stat, &stmt, sizeof(type_item),
             type_item, sizeof(res_buffer), res_buffer))
@@ -217,7 +217,7 @@ void firebird_statement_backend::rewriteQuery(
         prepareSQLDA(&sqldap_);
     }
 
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
     isc_stmt_handle tmpStmtp = 0;
 
     // allocate temporary statement to determine its type
@@ -300,7 +300,7 @@ void firebird_statement_backend::prepare(std::string const & query,
     // firebird's api
     rewriteQuery(query, queryBuffer);
 
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
 
     // prepare real statement
     if (isc_dsql_prepare(stat, session_.current_transaction(), &stmtp_, 0,
@@ -374,7 +374,7 @@ namespace
 statement_backend::exec_fetch_result
 firebird_statement_backend::execute(int number)
 {
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
     XSQLDA *t = NULL;
 
     std::size_t usize = uses_.size();
@@ -481,7 +481,7 @@ firebird_statement_backend::fetch(int number)
     if (endOfRowSet_)
         return ef_no_data;
 
-    ISC_STATUS stat[stat_size];
+    ISC_STATUS stat[ISC_STATUS_LENGTH];
 
     for (size_t i = 0; i<static_cast<unsigned int>(sqldap_->sqld); ++i)
     {