[ovs-dev] [PATCH 12/13] ovsdb-datum: Add functions for parsing and formatting atoms, data.
Ben Pfaff
blp at nicira.com
Mon Jan 25 18:18:58 UTC 2010
These functions provide an alternative to JSON parsing and formatting that
is more human-friendly (and shorter).
These will be used in an upcoming commit to enhance ovs-vsctl.
---
lib/ovsdb-data.c | 362 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
lib/ovsdb-data.h | 19 +++
2 files changed, 381 insertions(+), 0 deletions(-)
diff --git a/lib/ovsdb-data.c b/lib/ovsdb-data.c
index 6d9edb4..7990f08 100644
--- a/lib/ovsdb-data.c
+++ b/lib/ovsdb-data.c
@@ -18,8 +18,12 @@
#include "ovsdb-data.h"
#include <assert.h>
+#include <ctype.h>
+#include <float.h>
+#include <inttypes.h>
#include <limits.h>
+#include "dynamic-string.h"
#include "hash.h"
#include "ovsdb-error.h"
#include "json.h"
@@ -351,6 +355,155 @@ ovsdb_atom_to_json(const union ovsdb_atom *atom, enum ovsdb_atomic_type type)
NOT_REACHED();
}
}
+
+/* Initializes 'atom' to a value of the given 'type' parsed from 's', which
+ * takes one of the following forms:
+ *
+ * - OVSDB_TYPE_INTEGER: A decimal integer optionally preceded by a sign.
+ *
+ * - OVSDB_TYPE_REAL: A floating-point number in the format accepted by
+ * strtod().
+ *
+ * - OVSDB_TYPE_BOOLEAN: "true", "yes", "on", "1" for true, or "false",
+ * "no", "off", or "0" for false.
+ *
+ * - OVSDB_TYPE_STRING: A JSON string if it begins with a quote, otherwise
+ * an arbitrary string.
+ *
+ * - OVSDB_TYPE_UUID: A UUID in RFC 4627 format.
+ */
+void
+ovsdb_atom_from_string(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
+ const char *s)
+{
+ switch (type) {
+ case OVSDB_TYPE_VOID:
+ NOT_REACHED();
+
+ case OVSDB_TYPE_INTEGER: {
+ long long int integer;
+ if (!str_to_llong(s, 10, &integer)) {
+ ovs_fatal(0, "%s is not a valid integer", s);
+ }
+ atom->integer = integer;
+ }
+ break;
+
+ case OVSDB_TYPE_REAL:
+ if (!str_to_double(s, &atom->real)) {
+ ovs_fatal(0, "%s is not a valid real number", s);
+ }
+ break;
+
+ case OVSDB_TYPE_BOOLEAN:
+ if (!strcmp(s, "true") || !strcmp(s, "yes") || !strcmp(s, "on")
+ || !strcmp(s, "1")) {
+ atom->boolean = true;
+ } else if (!strcmp(s, "false") || !strcmp(s, "no") || !strcmp(s, "off")
+ || !strcmp(s, "0")) {
+ atom->boolean = false;
+ } else {
+ ovs_fatal(0, "%s is not a valid boolean "
+ "(use \"true\" or \"false\")", s);
+ }
+ break;
+
+ case OVSDB_TYPE_STRING:
+ if (*s == '\0') {
+ ovs_fatal(0, "use \"\" to represent the empty string");
+ } else if (*s == '"') {
+ size_t s_len = strlen(s);
+
+ if (s_len < 2 || s[s_len - 1] != '"') {
+ ovs_fatal(0, "%s: missing quote at end of quoted string", s);
+ } else if (!json_string_unescape(s + 1, s_len - 2,
+ &atom->string)) {
+ ovs_fatal(0, "%s: %s", s, atom->string);
+ }
+ } else {
+ atom->string = xstrdup(s);
+ }
+ break;
+
+ case OVSDB_TYPE_UUID:
+ if (!uuid_from_string(&atom->uuid, s)) {
+ ovs_fatal(0, "%s is not a valid UUID", s);
+ }
+ break;
+
+ case OVSDB_N_TYPES:
+ default:
+ NOT_REACHED();
+ }
+}
+
+static bool
+string_needs_quotes(const char *s)
+{
+ const char *p = s;
+ unsigned char c;
+
+ c = *p++;
+ if (!isalpha(c) && c != '_') {
+ return true;
+ }
+
+ while ((c = *p++) != '\0') {
+ if (!isalpha(c) && c != '_' && c != '-' && c != '.') {
+ return true;
+ }
+ }
+
+ if (!strcmp(s, "true") || !strcmp(s, "false")) {
+ return true;
+ }
+
+ return false;
+}
+
+/* Appends 'atom' (which has the given 'type') to 'out', in a format acceptable
+ * to ovsdb_atom_from_string(). */
+void
+ovsdb_atom_to_string(const union ovsdb_atom *atom, enum ovsdb_atomic_type type,
+ struct ds *out)
+{
+ switch (type) {
+ case OVSDB_TYPE_VOID:
+ NOT_REACHED();
+
+ case OVSDB_TYPE_INTEGER:
+ ds_put_format(out, "%"PRId64, atom->integer);
+ break;
+
+ case OVSDB_TYPE_REAL:
+ ds_put_format(out, "%.*g", DBL_DIG, atom->real);
+ break;
+
+ case OVSDB_TYPE_BOOLEAN:
+ ds_put_cstr(out, atom->boolean ? "true" : "false");
+ break;
+
+ case OVSDB_TYPE_STRING:
+ if (string_needs_quotes(atom->string)) {
+ struct json json;
+
+ json.type = JSON_STRING;
+ json.u.string = atom->string;
+ json_to_ds(&json, 0, out);
+ } else {
+ ds_put_cstr(out, atom->string);
+ }
+ break;
+
+ case OVSDB_TYPE_UUID:
+ ds_put_format(out, UUID_FMT, UUID_ARGS(&atom->uuid));
+ break;
+
+ case OVSDB_N_TYPES:
+ default:
+ NOT_REACHED();
+ }
+}
static union ovsdb_atom *
alloc_default_atoms(enum ovsdb_atomic_type type, size_t n)
@@ -643,6 +796,159 @@ ovsdb_datum_to_json(const struct ovsdb_datum *datum,
}
}
+static const char *
+skip_spaces(const char *p)
+{
+ return p + strspn(p, " ");
+}
+
+static const char *
+parse_key_value(const char *s, const struct ovsdb_type *type,
+ union ovsdb_atom *key, union ovsdb_atom *value)
+{
+ char *key_string;
+ const char *p;
+
+ /* Parse key. */
+ p = ovsdb_token_parse(s, &key_string);
+ ovsdb_atom_from_string(key, type->key_type, key_string);
+ free(key_string);
+
+ /* Parse value. */
+ if (type->value_type != OVSDB_TYPE_VOID) {
+ char *value_string;
+
+ if (*p != '=') {
+ ovs_fatal(0, "%s: syntax error at \"%c\" expecting \"=\"",
+ s, *p);
+ }
+ p = ovsdb_token_parse(p + 1, &value_string);
+ ovsdb_atom_from_string(value, type->value_type, value_string);
+ free(value_string);
+ }
+ return p;
+}
+
+static void
+free_key_value(const struct ovsdb_type *type,
+ union ovsdb_atom *key, union ovsdb_atom *value)
+{
+ ovsdb_atom_destroy(key, type->key_type);
+ if (type->value_type != OVSDB_TYPE_VOID) {
+ ovsdb_atom_destroy(value, type->value_type);
+ }
+}
+
+/* Initializes 'datum' as a datum of the given 'type', parsing its contents
+ * from 's'. The format of 's' is a series of space or comma separated atoms
+ * or, for a map, '='-delimited pairs of atoms. Each atom must in a format
+ * acceptable to ovsdb_atom_from_string(). Optionally, a set may be enclosed
+ * in "[]" or a map in "{}"; for an empty set or map these punctuators are
+ * required. */
+void
+ovsdb_datum_from_string(struct ovsdb_datum *datum,
+ const struct ovsdb_type *type, const char *s)
+{
+ bool is_map = ovsdb_type_is_map(type);
+ const char *p;
+ int end_delim;
+
+ ovsdb_datum_init_empty(datum);
+
+ /* Swallow a leading delimiter if there is one. */
+ p = skip_spaces(s);
+ if (*p == (is_map ? '{' : '[')) {
+ end_delim = is_map ? '}' : ']';
+ p = skip_spaces(p + 1);
+ } else if (!*p) {
+ if (is_map) {
+ ovs_fatal(0, "use \"{}\" to specify the empty map");
+ } else {
+ ovs_fatal(0, "use \"[]\" to specify the empty set");
+ }
+ } else {
+ end_delim = 0;
+ }
+
+ while (*p && *p != end_delim) {
+ union ovsdb_atom key, value;
+
+ if (ovsdb_token_is_delim(*p)) {
+ ovs_fatal(0, "%s: unexpected \"%c\" parsing %s",
+ s, *p, ovsdb_type_to_english(type));
+ }
+
+ /* Add to datum. */
+ p = parse_key_value(p, type, &key, &value);
+ ovsdb_datum_add_unsafe(datum, &key, &value, type);
+ free_key_value(type, &key, &value);
+
+ /* Skip optional white space and comma. */
+ p = skip_spaces(p);
+ if (*p == ',') {
+ p = skip_spaces(p + 1);
+ }
+ }
+
+ if (*p != end_delim) {
+ ovs_fatal(0, "%s: missing \"%c\" at end of data", s, end_delim);
+ }
+ if (end_delim) {
+ p = skip_spaces(p + 1);
+ if (*p) {
+ ovs_fatal(0, "%s: trailing garbage after \"%c\"", s, end_delim);
+ }
+ }
+
+ if (datum->n < type->n_min) {
+ ovs_fatal(0, "%s: %u %s were specified but at least %u are required",
+ s, datum->n,
+ type->value_type == OVSDB_TYPE_VOID ? "values" : "pairs",
+ type->n_min);
+ } else if (datum->n > type->n_max) {
+ ovs_fatal(0, "%s: %u %s were specified but at most %u are allowed",
+ s, datum->n,
+ type->value_type == OVSDB_TYPE_VOID ? "values" : "pairs",
+ type->n_max);
+ }
+
+ if (ovsdb_datum_sort(datum, type)) {
+ if (ovsdb_type_is_map(type)) {
+ ovs_fatal(0, "%s: map contains duplicate key", s);
+ } else {
+ ovs_fatal(0, "%s: set contains duplicate value", s);
+ }
+ }
+}
+
+/* Appends to 'out' the 'datum' (with the given 'type') in a format acceptable
+ * to ovsdb_datum_from_string(). */
+void
+ovsdb_datum_to_string(const struct ovsdb_datum *datum,
+ const struct ovsdb_type *type, struct ds *out)
+{
+ bool is_map = ovsdb_type_is_map(type);
+ size_t i;
+
+ if (type->n_max > 1 || !datum->n) {
+ ds_put_char(out, is_map ? '{' : '[');
+ }
+ for (i = 0; i < datum->n; i++) {
+ if (i > 0) {
+ ds_put_cstr(out, ", ");
+ }
+
+ ovsdb_atom_to_string(&datum->keys[i], type->key_type, out);
+ if (is_map) {
+ ds_put_char(out, '=');
+ ovsdb_atom_to_string(&datum->values[i], type->value_type, out);
+ }
+ }
+ if (type->n_max > 1 || !datum->n) {
+ ds_put_char(out, is_map ? '}' : ']');
+ }
+}
+
static uint32_t
hash_atoms(enum ovsdb_atomic_type type, const union ovsdb_atom *atoms,
unsigned int n, uint32_t basis)
@@ -972,3 +1278,59 @@ ovsdb_symbol_table_put(struct ovsdb_symbol_table *symtab, const char *name,
symbol->used = used;
shash_add(&symtab->sh, name, symbol);
}
+
+/* Extracts a token from the beginning of 's' and returns a pointer just after
+ * the token. Stores the token itself into '*outp', which the caller is
+ * responsible for freeing (with free()).
+ *
+ * If 's[0]' is a delimiter, the returned token is the empty string.
+ *
+ * A token extends from 's' to the first delimiter, as defined by
+ * ovsdb_token_is_delim(), or until the end of the string. A delimiter can be
+ * escaped with a backslash, in which case the backslash does not appear in the
+ * output. Double quotes also cause delimiters to be ignored, but the double
+ * quotes are retained in the output. (Backslashes inside double quotes are
+ * not removed, either.)
+ */
+const char *
+ovsdb_token_parse(const char *s, char **outp)
+{
+ const char *p;
+ struct ds out;
+ bool in_quotes;
+
+ ds_init(&out);
+ in_quotes = false;
+ for (p = s; *p != '\0'; ) {
+ int c = *p++;
+ if (c == '\\') {
+ if (in_quotes) {
+ ds_put_char(&out, '\\');
+ }
+ if (!*p) {
+ ovs_fatal(0, "%s: backslash at end of argument", s);
+ }
+ ds_put_char(&out, *p++);
+ } else if (!in_quotes && ovsdb_token_is_delim(c)) {
+ p--;
+ break;
+ } else {
+ ds_put_char(&out, c);
+ if (c == '"') {
+ in_quotes = !in_quotes;
+ }
+ }
+ }
+ if (in_quotes) {
+ ovs_fatal(0, "%s: quoted string extends past end of argument", s);
+ }
+ *outp = ds_cstr(&out);
+ return p;
+}
+
+/* Returns true if 'c' delimits tokens, or if 'c' is 0, and false otherwise. */
+bool
+ovsdb_token_is_delim(unsigned char c)
+{
+ return strchr(":=, []{}", c) != NULL;
+}
diff --git a/lib/ovsdb-data.h b/lib/ovsdb-data.h
index 9cada2f..70dfd0f 100644
--- a/lib/ovsdb-data.h
+++ b/lib/ovsdb-data.h
@@ -20,6 +20,7 @@
#include "compiler.h"
#include "ovsdb-types.h"
+struct ds;
struct ovsdb_symbol_table;
/* One value of an atomic type (given by enum ovs_atomic_type). */
@@ -72,6 +73,11 @@ struct ovsdb_error *ovsdb_atom_from_json(union ovsdb_atom *,
WARN_UNUSED_RESULT;
struct json *ovsdb_atom_to_json(const union ovsdb_atom *,
enum ovsdb_atomic_type);
+
+void ovsdb_atom_from_string(union ovsdb_atom *, enum ovsdb_atomic_type,
+ const char *);
+void ovsdb_atom_to_string(const union ovsdb_atom *, enum ovsdb_atomic_type,
+ struct ds *);
/* An instance of an OVSDB type (given by struct ovsdb_type).
*
@@ -122,6 +128,12 @@ struct ovsdb_error *ovsdb_datum_from_json(struct ovsdb_datum *,
struct json *ovsdb_datum_to_json(const struct ovsdb_datum *,
const struct ovsdb_type *);
+void ovsdb_datum_from_string(struct ovsdb_datum *,
+ const struct ovsdb_type *, const char *);
+void ovsdb_datum_to_string(const struct ovsdb_datum *,
+ const struct ovsdb_type *, struct ds *);
+
+/* Comparison. */
uint32_t ovsdb_datum_hash(const struct ovsdb_datum *,
const struct ovsdb_type *, uint32_t basis);
int ovsdb_datum_compare_3way(const struct ovsdb_datum *,
@@ -187,5 +199,12 @@ struct ovsdb_symbol *ovsdb_symbol_table_get(const struct ovsdb_symbol_table *,
const char *name);
void ovsdb_symbol_table_put(struct ovsdb_symbol_table *, const char *name,
const struct uuid *, bool used);
+
+/* Tokenization
+ *
+ * Used by ovsdb_atom_from_string() and ovsdb_datum_from_string(). */
+
+const char *ovsdb_token_parse(const char *, char **outp);
+bool ovsdb_token_is_delim(unsigned char);
#endif /* ovsdb-data.h */
--
1.6.3.3
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