[rrd-developers] [PATCH 2/4] src/rrd_client.[ch]: Add `rrdc_fetch'.
Florian Forster
rrdtool at nospam.verplant.org
Tue Mar 24 16:40:14 CET 2009
From: Florian Forster <octo at leeloo.lan.home.verplant.org>
The `rrdc_fetch' command has the same interface as `rrd_fetch_r' and
behaves just like it, except that it will read the value from the RRD
caching daemon, using the `FETCH' command.
Signed-off-by: Florian Forster <octo at leeloo.lan.home.verplant.org>
---
src/rrd_client.c | 340 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
src/rrd_client.h | 10 ++-
2 files changed, 348 insertions(+), 2 deletions(-)
diff --git a/src/rrd_client.c b/src/rrd_client.c
index 8e60664..602a1ee 100644
--- a/src/rrd_client.c
+++ b/src/rrd_client.c
@@ -1,6 +1,6 @@
/**
* RRDTool - src/rrd_client.c
- * Copyright (C) 2008 Florian octo Forster
+ * Copyright (C) 2008,2009 Florian octo Forster
*
* 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
@@ -51,6 +51,137 @@ static int sd = -1;
static FILE *sh = NULL;
static char *sd_path = NULL; /* cache the path for sd */
+static size_t strsplit (char *string, char **fields, size_t size) /* {{{ */
+{
+ size_t i;
+ char *ptr;
+ char *saveptr;
+
+ i = 0;
+ ptr = string;
+ saveptr = NULL;
+ while ((fields[i] = strtok_r (ptr, " \t\r\n", &saveptr)) != NULL)
+ {
+ ptr = NULL;
+ i++;
+
+ if (i >= size)
+ break;
+ }
+
+ return (i);
+} /* }}} size_t strsplit */
+
+static int parse_header (char *line, /* {{{ */
+ char **ret_key, char **ret_value)
+{
+ char *tmp;
+
+ *ret_key = line;
+
+ tmp = strchr (line, ':');
+ if (tmp == NULL)
+ return (-1);
+
+ do
+ {
+ *tmp = 0;
+ tmp++;
+ }
+ while ((tmp[0] == ' ') || (tmp[0] == '\t'));
+
+ if (*tmp == 0)
+ return (-1);
+
+ *ret_value = tmp;
+ return (0);
+} /* }}} int parse_header */
+
+static int parse_ulong_header (char *line, /* {{{ */
+ char **ret_key, unsigned long *ret_value)
+{
+ char *str_value;
+ char *endptr;
+ int status;
+
+ str_value = NULL;
+ status = parse_header (line, ret_key, &str_value);
+ if (status != 0)
+ return (status);
+
+ endptr = NULL;
+ errno = 0;
+ *ret_value = (unsigned long) strtol (str_value, &endptr, /* base = */ 0);
+ if ((endptr == str_value) || (errno != 0))
+ return (-1);
+
+ return (0);
+} /* }}} int parse_ulong_header */
+
+static int parse_char_array_header (char *line, /* {{{ */
+ char **ret_key, char **array, size_t array_len, int alloc)
+{
+ char *tmp_array[array_len];
+ char *value;
+ size_t num;
+ int status;
+
+ value = NULL;
+ status = parse_header (line, ret_key, &value);
+ if (status != 0)
+ return (-1);
+
+ num = strsplit (value, tmp_array, array_len);
+ if (num != array_len)
+ return (-1);
+
+ if (alloc == 0)
+ {
+ memcpy (array, tmp_array, sizeof (tmp_array));
+ }
+ else
+ {
+ size_t i;
+
+ for (i = 0; i < array_len; i++)
+ array[i] = strdup (tmp_array[i]);
+ }
+
+ return (0);
+} /* }}} int parse_char_array_header */
+
+static int parse_value_array_header (char *line, /* {{{ */
+ time_t *ret_time, rrd_value_t *array, size_t array_len)
+{
+ char *str_key;
+ char *str_array[array_len];
+ char *endptr;
+ int status;
+ size_t i;
+
+ str_key = NULL;
+ status = parse_char_array_header (line, &str_key,
+ str_array, array_len, /* alloc = */ 0);
+ if (status != 0)
+ return (-1);
+
+ errno = 0;
+ endptr = NULL;
+ *ret_time = (time_t) strtol (str_key, &endptr, /* base = */ 10);
+ if ((endptr == str_key) || (errno != 0))
+ return (-1);
+
+ for (i = 0; i < array_len; i++)
+ {
+ endptr = NULL;
+ array[i] = (rrd_value_t) strtod (str_array[i], &endptr);
+ if ((endptr == str_array[i]) || (errno != 0))
+ return (-1);
+ }
+
+ return (0);
+} /* }}} int parse_value_array_header */
+
/* One must hold `lock' when calling `close_connection'. */
static void close_connection (void) /* {{{ */
{
@@ -604,6 +735,213 @@ int rrdc_flush (const char *filename) /* {{{ */
return (status);
} /* }}} int rrdc_flush */
+int rrdc_fetch (const char *filename, /* {{{ */
+ const char *cf,
+ time_t *ret_start, time_t *ret_end,
+ unsigned long *ret_step,
+ unsigned long *ret_ds_num,
+ char ***ret_ds_names,
+ rrd_value_t **ret_data)
+{
+ char buffer[4096];
+ char *buffer_ptr;
+ size_t buffer_free;
+ size_t buffer_size;
+ rrdc_response_t *res;
+ char file_path[PATH_MAX];
+
+ char *str_tmp;
+ unsigned long flush_version;
+
+ time_t start;
+ time_t end;
+ unsigned long step;
+ unsigned long ds_num;
+ char **ds_names;
+
+ rrd_value_t *data;
+ size_t data_size;
+ size_t data_fill;
+
+ int status;
+ size_t current_line;
+ time_t t;
+
+ if ((filename == NULL) || (cf == NULL))
+ return (-1);
+
+ /* Send request {{{ */
+ memset (buffer, 0, sizeof (buffer));
+ buffer_ptr = &buffer[0];
+ buffer_free = sizeof (buffer);
+
+ status = buffer_add_string ("FETCH", &buffer_ptr, &buffer_free);
+ if (status != 0)
+ return (ENOBUFS);
+
+ /* change to absolute path for rrdcached */
+ if (*filename != '/' && realpath(filename, file_path) != NULL)
+ filename = file_path;
+
+ status = buffer_add_string (filename, &buffer_ptr, &buffer_free);
+ if (status != 0)
+ return (ENOBUFS);
+
+ status = buffer_add_string (cf, &buffer_ptr, &buffer_free);
+ if (status != 0)
+ return (ENOBUFS);
+
+ if ((ret_start != NULL) && (*ret_start > 0))
+ {
+ char tmp[64];
+ snprintf (tmp, sizeof (tmp), "%lu", (unsigned long) *ret_start);
+ tmp[sizeof (tmp) - 1] = 0;
+ status = buffer_add_string (tmp, &buffer_ptr, &buffer_free);
+ if (status != 0)
+ return (ENOBUFS);
+
+ if ((ret_end != NULL) && (*ret_end > 0))
+ {
+ snprintf (tmp, sizeof (tmp), "%lu", (unsigned long) *ret_end);
+ tmp[sizeof (tmp) - 1] = 0;
+ status = buffer_add_string (tmp, &buffer_ptr, &buffer_free);
+ if (status != 0)
+ return (ENOBUFS);
+ }
+ }
+
+ assert (buffer_free < sizeof (buffer));
+ buffer_size = sizeof (buffer) - buffer_free;
+ assert (buffer[buffer_size - 1] == ' ');
+ buffer[buffer_size - 1] = '\n';
+
+ res = NULL;
+ status = request (buffer, buffer_size, &res);
+ if (status != 0)
+ return (status);
+
+ status = res->status;
+ if (status < 0)
+ {
+ rrd_set_error ("rrdcached: %s", res->message);
+ response_free (res);
+ return (status);
+ }
+ /* }}} Send request */
+
+ ds_names = NULL;
+ ds_num = 0;
+ data = NULL;
+ current_line = 0;
+
+ /* Macros to make error handling a little easier (i. e. less to type and
+ * read. `BAIL_OUT' sets the error message, frees all dynamically allocated
+ * variables and returns the provided status code. */
+#define BAIL_OUT(status, ...) do { \
+ rrd_set_error ("rrdc_fetch: " __VA_ARGS__); \
+ free (data); \
+ if (ds_names != 0) { size_t k; for (k = 0; k < ds_num; k++) free (ds_names[k]); } \
+ free (ds_names); \
+ response_free (res); \
+ return (status); \
+ } while (0)
+
+#define READ_NUMERIC_FIELD(name,type,var) do { \
+ char *key; \
+ unsigned long value; \
+ assert (current_line < res->lines_num); \
+ status = parse_ulong_header (res->lines[current_line], &key, &value); \
+ if (status != 0) \
+ BAIL_OUT (-1, "Unable to parse header `%s'", name); \
+ if (strcasecmp (key, name) != 0) \
+ BAIL_OUT (-1, "Unexpected header line: Expected `%s', got `%s'", name, key); \
+ var = (type) value; \
+ current_line++; \
+ } while (0)
+
+ if (res->lines_num < 1)
+ BAIL_OUT (-1, "Premature end of response packet");
+
+ /* We're making some very strong assumptions about the fields below. We
+ * therefore check the version of the `flush' command first, so that later
+ * versions can change the order of fields and it's easier to implement
+ * backwards compatibility. */
+ READ_NUMERIC_FIELD ("FlushVersion", unsigned long, flush_version);
+ if (flush_version != 1)
+ BAIL_OUT (-1, "Don't know how to handle flush format version %lu.",
+ flush_version);
+
+ if (res->lines_num < 5)
+ BAIL_OUT (-1, "Premature end of response packet");
+
+ READ_NUMERIC_FIELD ("Start", time_t, start);
+ READ_NUMERIC_FIELD ("End", time_t, end);
+ if (start >= end)
+ BAIL_OUT (-1, "Malformed start and end times: start = %lu; end = %lu;",
+ (unsigned long) start,
+ (unsigned long) end);
+
+ READ_NUMERIC_FIELD ("Step", unsigned long, step);
+ if (step < 1)
+ BAIL_OUT (-1, "Invalid number for Step: %lu", step);
+
+ READ_NUMERIC_FIELD ("DSCount", unsigned long, ds_num);
+ if (ds_num < 1)
+ BAIL_OUT (-1, "Invalid number for DSCount: %lu", ds_num);
+
+ /* It's time to allocate some memory */
+ ds_names = calloc ((size_t) ds_num, sizeof (*ds_names));
+ if (ds_names == NULL)
+ BAIL_OUT (-1, "Out of memory");
+
+ status = parse_char_array_header (res->lines[current_line],
+ &str_tmp, ds_names, (size_t) ds_num, /* alloc = */ 1);
+ if (status != 0)
+ BAIL_OUT (-1, "Unable to parse header `DSName'");
+ if (strcasecmp ("DSName", str_tmp) != 0)
+ BAIL_OUT (-1, "Unexpected header line: Expected `DSName', got `%s'", str_tmp);
+ current_line++;
+
+ data_size = ds_num * (end - start) / step;
+ if (data_size < 1)
+ BAIL_OUT (-1, "No data returned or headers invalid.");
+
+ if (res->lines_num != (6 + (data_size / ds_num)))
+ BAIL_OUT (-1, "Got %zu lines, expected %zu",
+ res->lines_num, (6 + (data_size / ds_num)));
+
+ data = calloc (data_size, sizeof (*data));
+ if (data == NULL)
+ BAIL_OUT (-1, "Out of memory");
+
+
+ data_fill = 0;
+ for (t = start + step; t <= end; t += step, current_line++)
+ {
+ time_t tmp;
+
+ assert (current_line < res->lines_num);
+
+ status = parse_value_array_header (res->lines[current_line],
+ &tmp, data + data_fill, (size_t) ds_num);
+ if (status != 0)
+ BAIL_OUT (-1, "Cannot parse value line");
+
+ data_fill += (size_t) ds_num;
+ }
+
+ *ret_start = start;
+ *ret_end = end;
+ *ret_step = step;
+ *ret_ds_num = ds_num;
+ *ret_ds_names = ds_names;
+ *ret_data = data;
+
+ response_free (res);
+ return (0);
+#undef READ_NUMERIC_FIELD
+#undef BAIL_OUT
+} /* }}} int rrdc_flush */
/* convenience function; if there is a daemon specified, or if we can
* detect one from the environment, then flush the file. Otherwise, no-op
diff --git a/src/rrd_client.h b/src/rrd_client.h
index 90b78f8..9f58af6 100644
--- a/src/rrd_client.h
+++ b/src/rrd_client.h
@@ -1,6 +1,6 @@
/**
* RRDTool - src/rrd_client.h
- * Copyright (C) 2008 Florian octo Forster
+ * Copyright (C) 2008,2009 Florian octo Forster
*
* 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
@@ -58,6 +58,14 @@ int rrdc_update (const char *filename, int values_num,
int rrdc_flush (const char *filename);
int rrdc_flush_if_daemon (const char *opt_daemon, const char *filename);
+int rrdc_fetch (const char *filename,
+ const char *cf,
+ time_t *ret_start, time_t *ret_end,
+ unsigned long *ret_step,
+ unsigned long *ret_ds_num,
+ char ***ret_ds_names,
+ rrd_value_t **ret_data);
+
#else
# define rrdc_flush_if_daemon(a,b) 0
# define rrdc_connect(a) 0
--
1.6.2
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