csvparser: add filterx-func-format-csv function

Signed-off-by: shifter <shifter@axoflow.com>

modules/csvparser/CMakeLists.txt

@@ -6,6 +6,8 @@ set(CSVPARSER_SOURCES
     csvparser-plugin.c
     filterx-func-parse-csv.h
     filterx-func-parse-csv.c
+    filterx-func-format-csv.h
+    filterx-func-format-csv.c
 )
 
 add_module(

modules/csvparser/Makefile.am

@@ -7,7 +7,9 @@ modules_csvparser_libcsvparser_la_SOURCES	=	\
 	modules/csvparser/csvparser-parser.h		\
 	modules/csvparser/csvparser-plugin.c		\
 	modules/csvparser/filterx-func-parse-csv.h  \
-	modules/csvparser/filterx-func-parse-csv.c
+	modules/csvparser/filterx-func-parse-csv.c	\
+	modules/csvparser/filterx-func-format-csv.h  \
+	modules/csvparser/filterx-func-format-csv.c
 
 modules_csvparser_libcsvparser_la_CPPFLAGS	=	\
 	$(AM_CPPFLAGS)					\

modules/csvparser/csvparser-plugin.c

@@ -26,6 +26,7 @@
 #include "plugin.h"
 #include "plugin-types.h"
 #include "filterx-func-parse-csv.h"
+#include "filterx-func-format-csv.h"
 
 extern CfgParser csvparser_parser;
 
@@ -41,6 +42,11 @@ static Plugin csvparser_plugins[] =
     .name = "parse_csv",
     .construct = filterx_function_construct_parse_csv,
   },
+  {
+    .type =  LL_CONTEXT_FILTERX_FUNC,
+    .name = "format_csv",
+    .construct = filterx_function_construct_format_csv,
+  },
 };
 
 gboolean

modules/csvparser/filterx-func-format-csv.c

@@ -0,0 +1,255 @@
+/*
+ * Copyright (c) 2024 shifter
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, or (at your option) any later version.
+ *
+ * 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
+ *
+ * As an additional exemption you are allowed to compile & link against the
+ * OpenSSL libraries as published by the OpenSSL project. See the file
+ * COPYING for details.
+ *
+ */
+
+#include "filterx-func-format-csv.h"
+#include "filterx/expr-literal.h"
+#include "filterx/object-string.h"
+#include "filterx/object-null.h"
+#include "filterx/object-dict-interface.h"
+#include "filterx/object-list-interface.h"
+#include "filterx/filterx-eval.h"
+
+#include "scratch-buffers.h"
+#include "utf8utils.h"
+
+#define FILTERX_FUNC_FORMAT_CSV_USAGE "Usage: format_csv(csv_dict or csv_array)"
+
+typedef struct FilterXFunctionFormatCSV_
+{
+  FilterXFunction super;
+  FilterXExpr *input;
+  gchar delimiter;
+  FilterXExpr *columns;
+} FilterXFunctionFormatCSV;
+
+static gboolean
+_append_to_buffer(FilterXObject *key, FilterXObject *value, gpointer user_data)
+{
+  if (!value)
+    return FALSE;
+
+  FilterXFunctionFormatCSV *self = ((gpointer *) user_data)[0];
+  GString *buffer = ((gpointer *) user_data)[1];
+
+  if (filterx_object_is_type(value, &FILTERX_TYPE_NAME(dict)) ||
+      filterx_object_is_type(value, &FILTERX_TYPE_NAME(list)))
+    {
+      msg_debug("FilterX: format_csv(): skipping object, type not supported",
+                evt_tag_str("type", value->type->name));
+      return TRUE;
+    }
+
+  if (buffer->len)
+    g_string_append(buffer, &self->delimiter);
+
+  gsize len_before_value = buffer->len;
+  if (!filterx_object_repr_append(value, buffer))
+    return FALSE;
+
+  /* TODO: make the characters here configurable. */
+  if (memchr(buffer->str + len_before_value, self->delimiter, buffer->len - len_before_value) != NULL)
+    {
+      ScratchBuffersMarker marker;
+      GString *value_buffer = scratch_buffers_alloc_and_mark(&marker);
+
+      g_string_assign(value_buffer, buffer->str + len_before_value);
+      g_string_truncate(buffer, len_before_value);
+      g_string_append_c(buffer, '"');
+      append_unsafe_utf8_as_escaped_binary(buffer, value_buffer->str, value_buffer->len, "\"");
+      g_string_append_c(buffer, '"');
+
+      scratch_buffers_reclaim_marked(marker);
+    }
+
+  return TRUE;
+}
+
+static FilterXObject *
+_eval(FilterXExpr *s)
+{
+  FilterXFunctionFormatCSV *self = (FilterXFunctionFormatCSV *) s;
+
+  FilterXObject *csv_data = filterx_expr_eval_typed(self->input);
+  if (!csv_data)
+    {
+      filterx_eval_push_error("Failed to evaluate input. " FILTERX_FUNC_FORMAT_CSV_USAGE, s, NULL);
+      return NULL;
+    }
+
+  gboolean success = FALSE;
+  GString *formatted = scratch_buffers_alloc();
+
+  if (filterx_object_is_type(csv_data, &FILTERX_TYPE_NAME(list)))
+    {
+      guint64 size;
+      if (!filterx_object_len(csv_data, &size))
+        return FALSE;
+
+      gpointer user_data[] = { self, formatted };
+      success = TRUE;
+      for (guint64 i = 0; i < size && success; i++)
+        {
+          FilterXObject *elt = filterx_list_get_subscript(csv_data, i);
+          success = _append_to_buffer(NULL, elt, user_data);
+          filterx_object_unref(elt);
+        }
+    }
+  else if (filterx_object_is_type(csv_data, &FILTERX_TYPE_NAME(dict)))
+    {
+      if (self->columns)
+        {
+          FilterXObject *cols = filterx_expr_eval(self->columns);
+          if (filterx_object_is_type(cols, &FILTERX_TYPE_NAME(list)))
+            {
+              guint64 size;
+              if (!filterx_object_len(cols, &size))
+                return FALSE;
+
+              gpointer user_data[] = { self, formatted };
+              success = TRUE;
+              for (guint64 i = 0; i < size && success; i++)
+                {
+                  FilterXObject *col = filterx_list_get_subscript(cols, i);
+                  FilterXObject *elt = filterx_object_get_subscript(csv_data, col);
+                  success = _append_to_buffer(col, elt, user_data);
+                  filterx_object_unref(col);
+                  filterx_object_unref(elt);
+                }
+            }
+          filterx_object_unref(cols);
+        }
+      else
+        {
+          gpointer user_data[] = { self, formatted };
+          success = filterx_dict_iter(csv_data, _append_to_buffer, user_data);
+        }
+    }
+  else
+    {
+      filterx_eval_push_error("input must be a dict or list. " FILTERX_FUNC_FORMAT_CSV_USAGE, s, csv_data);
+      filterx_object_unref(csv_data);
+      return NULL;
+    }
+
+  filterx_object_unref(csv_data);
+  return success ? filterx_string_new(formatted->str, formatted->len) : NULL;
+}
+
+static void
+_free(FilterXExpr *s)
+{
+  FilterXFunctionFormatCSV *self = (FilterXFunctionFormatCSV *) s;
+
+  filterx_expr_unref(self->input);
+  filterx_expr_unref(self->columns);
+  filterx_function_free_method(&self->super);
+}
+
+static FilterXExpr *
+_extract_columns_expr(FilterXFunctionArgs *args, GError **error)
+{
+  return filterx_function_args_get_named_expr(args, FILTERX_FUNC_FORMAT_CSV_ARG_NAME_COLUMNS);
+}
+
+static gboolean
+_extract_delimiter_arg(FilterXFunctionFormatCSV *self, FilterXFunctionArgs *args, GError **error)
+{
+  gboolean exists;
+  gsize delimiter_len;
+  const gchar *delimiter = filterx_function_args_get_named_literal_string(args,
+                           FILTERX_FUNC_FORMAT_CSV_ARG_NAME_DELIMITER,
+                           &delimiter_len, &exists);
+  if (!exists)
+    return TRUE;
+
+  if (!delimiter)
+    {
+      g_set_error(error, FILTERX_FUNCTION_ERROR, FILTERX_FUNCTION_ERROR_CTOR_FAIL,
+                  "delimiter must be a string literal. " FILTERX_FUNC_FORMAT_CSV_USAGE);
+      return FALSE;
+    }
+
+  if (delimiter_len != 1)
+    {
+      g_set_error(error, FILTERX_FUNCTION_ERROR, FILTERX_FUNCTION_ERROR_CTOR_FAIL,
+                  "delimiter must be a single character. " FILTERX_FUNC_FORMAT_CSV_USAGE);
+      return FALSE;
+    }
+
+  self->delimiter = delimiter[0];
+  return TRUE;
+}
+
+static gboolean
+_extract_arguments(FilterXFunctionFormatCSV *self, FilterXFunctionArgs *args, GError **error)
+{
+  gsize args_len = filterx_function_args_len(args);
+  if (args_len != 1)
+    {
+      g_set_error(error, FILTERX_FUNCTION_ERROR, FILTERX_FUNCTION_ERROR_CTOR_FAIL,
+                  "invalid number of arguments. " FILTERX_FUNC_FORMAT_CSV_USAGE);
+      return FALSE;
+    }
+
+  self->input = filterx_function_args_get_expr(args, 0);
+  if (!self->input)
+    {
+      g_set_error(error, FILTERX_FUNCTION_ERROR, FILTERX_FUNCTION_ERROR_CTOR_FAIL,
+                  "input must be set. " FILTERX_FUNC_FORMAT_CSV_USAGE);
+      return FALSE;
+    }
+
+  if (!_extract_delimiter_arg(self, args, error))
+    return FALSE;
+
+  self->columns = _extract_columns_expr(args, error);
+
+  return TRUE;
+}
+
+FilterXFunction *
+filterx_function_format_csv_new(const gchar *function_name, FilterXFunctionArgs *args, GError **error)
+{
+  FilterXFunctionFormatCSV *self = g_new0(FilterXFunctionFormatCSV, 1);
+  filterx_function_init_instance(&self->super, function_name);
+
+  self->super.super.eval = _eval;
+  self->super.super.free_fn = _free;
+  self->delimiter = ',';
+
+  if (!_extract_arguments(self, args, error))
+    goto error;
+
+  filterx_function_args_free(args);
+  return &self->super;
+
+error:
+  filterx_function_args_free(args);
+  filterx_expr_unref(&self->super.super);
+  return NULL;
+}
+
+gpointer
+filterx_function_construct_format_csv(Plugin *self)
+{
+  return (gpointer) filterx_function_format_csv_new;
+}

modules/csvparser/filterx-func-format-csv.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2024 shifter
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation, or (at your option) any later version.
+ *
+ * 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
+ *
+ * As an additional exemption you are allowed to compile & link against the
+ * OpenSSL libraries as published by the OpenSSL project. See the file
+ * COPYING for details.
+ *
+ */
+
+#ifndef FILTERX_FUNC_FORMAT_CSV_H_INCLUDED
+#define FILTERX_FUNC_FORMAT_CSV_H_INCLUDED
+
+
+#include "plugin.h"
+#include "filterx/expr-function.h"
+
+#define FILTERX_FUNC_FORMAT_CSV_ARG_NAME_COLUMNS "columns"
+#define FILTERX_FUNC_FORMAT_CSV_ARG_NAME_DELIMITER "delimiter"
+
+FilterXFunction *filterx_function_format_csv_new(const gchar *function_name, FilterXFunctionArgs *args, GError **error);
+gpointer filterx_function_construct_format_csv(Plugin *self);
+
+#endif