[pulseaudio-discuss] [PATCH 8/8] message-params: Add read functions for arrays

Georg Chini georg at chini.tk
Mon Apr 9 17:35:25 UTC 2018


---
 doc/messaging_api.txt      |   5 ++
 src/map-file               |   4 +
 src/pulse/message-params.c | 202 +++++++++++++++++++++++++++++++++++++++++++++
 src/pulse/message-params.h |  12 +++
 4 files changed, 223 insertions(+)

diff --git a/doc/messaging_api.txt b/doc/messaging_api.txt
index d080b783..57a92f58 100644
--- a/doc/messaging_api.txt
+++ b/doc/messaging_api.txt
@@ -53,6 +53,11 @@ pa_message_param_read_double() - read a double from a parameter list
 pa_message_param_read_int64() - read an integer from a parameter list
 pa_message_param_read_uint64() - read an unsigned from a parameter list
 pa_message_param_read_bool() - read a boolean from a parameter list
+pa_message_param_read_double_array() - read an array of double from list
+pa_message_param_read_int64_array() - read an array of int64 from list
+pa_message_param_read_uint64_array() - read an array of uint64 from list
+pa_message_param_read_string_array() - read an array of strings from a list
+
 
 All read functions return 1 on success, 0 if end of string is found and -1 on
 parse error. Additionally, for the numeric/boolean read functions, 2 is returned
diff --git a/src/map-file b/src/map-file
index ab8c21c6..88d892ef 100644
--- a/src/map-file
+++ b/src/map-file
@@ -230,9 +230,13 @@ pa_message_param_end_list;
 pa_message_param_new;
 pa_message_param_read_bool;
 pa_message_param_read_double;
+pa_message_param_read_double_array;
 pa_message_param_read_int64;
+pa_message_param_read_int64_array;
 pa_message_param_read_string;
+pa_message_param_read_string_array;
 pa_message_param_read_uint64;
+pa_message_param_read_uint64_array;
 pa_message_param_split_list;
 pa_message_param_to_string;
 pa_message_param_write_bool;
diff --git a/src/pulse/message-params.c b/src/pulse/message-params.c
index 93972399..b9846863 100644
--- a/src/pulse/message-params.c
+++ b/src/pulse/message-params.c
@@ -38,6 +38,8 @@ struct pa_message_param {
     pa_strbuf *buffer;
 };
 
+/* Helper functions */
+
 /* Remove escaping from a string */
 static char *unescape(char *value) {
     char *tmp;
@@ -62,6 +64,59 @@ static char *unescape(char *value) {
     return value;
 }
 
+/* Count number of top level elements in parameter list */
+static int count_elements(const char *c) {
+    const char *s;
+    uint32_t element_count;
+    bool found_element, found_backslash;
+    int open_braces;
+
+    if (!c || *c == 0)
+        return PA_PARAM_LIST_END;
+
+    element_count = 0;
+    open_braces = 0;
+    found_element = false;
+    found_backslash = false;
+    s = c;
+
+    /* Count elements in list */
+    while (*s != 0) {
+
+        /* Skip escaped curly braces. */
+        if (*s == '\\') {
+            found_backslash = true;
+            s++;
+            continue;
+        }
+
+        if (*s == '{' && !found_backslash) {
+            found_element = true;
+            open_braces++;
+        }
+        if (*s == '}' && !found_backslash)
+            open_braces--;
+
+        /* unexpected closing brace, parse error */
+        if (open_braces < 0)
+            return PA_PARAM_PARSE_ERROR;
+
+        if (open_braces == 0 && found_element) {
+            element_count++;
+            found_element = false;
+        }
+
+        found_backslash = false;
+        s++;
+    }
+
+    /* missing closing brace, parse error */
+    if (open_braces > 0)
+        return PA_PARAM_PARSE_ERROR;
+
+    return element_count;
+}
+
 /* Read functions */
 
 /* Split the specified string into elements. An element is defined as
@@ -300,6 +355,153 @@ int pa_message_param_read_bool(char *c, bool *result, void **state) {
     return PA_PARAM_OK;
 }
 
+/* Converts a parameter list to a string array. Escaping is removed
+ * from a string if the string does not contain a list. If allocate
+ * is true, new strings will be allocated, otherwise pointers to
+ * sub-strings within c will be returned. */
+int pa_message_param_read_string_array(char *c, char ***parameter_list, bool allocate) {
+    char *start_pos;
+    void *state = NULL;
+    uint32_t element_count, i;
+    bool is_unpacked;
+    int err;
+
+    pa_assert(parameter_list);
+
+    *parameter_list = NULL;
+
+    /* Count elements, return if no element was found or parse error. */
+    if ((element_count = count_elements(c)) <= 0)
+        return element_count;
+
+    /* Allocate array */
+    *parameter_list = pa_xmalloc0(element_count * sizeof(char *));
+
+    i = 0;
+    while ((err = pa_message_param_split_list(c, &start_pos, &is_unpacked, &state)) > 0) {
+        (*parameter_list)[i] = start_pos;
+        if (is_unpacked)
+            (*parameter_list)[i] = unescape(start_pos);
+
+        /* If new strings are allocated, they must be freed by the caller */
+        if (allocate)
+            (*parameter_list)[i] = pa_xstrdup((*parameter_list)[i]);
+
+        i++;
+    }
+
+    if (err < 0) {
+        if (allocate) {
+            for (i = 0; i < element_count; i++)
+                pa_xfree((*parameter_list)[i]);
+        }
+        pa_xfree(*parameter_list);
+        *parameter_list = NULL;
+        return PA_PARAM_PARSE_ERROR;
+    }
+
+    return element_count;
+}
+
+/* Converts a parameter list to a double array. */
+int pa_message_param_read_double_array(char *c, double **parameter_list) {
+    double  value;
+    void *state = NULL;
+    uint32_t element_count, i;
+    int err;
+
+    pa_assert(parameter_list);
+
+    *parameter_list = NULL;
+
+    /* Count elements, return if no element was found or parse error. */
+    if ((element_count = count_elements(c)) <= 0)
+        return element_count;
+
+    /* Allocate array */
+    *parameter_list = pa_xmalloc(element_count * sizeof(double));
+
+    i = 0;
+    while ((err = pa_message_param_read_double(c, &value, &state)) > 0) {
+       (*parameter_list)[i] = value;
+        i++;
+    }
+
+    if (err < 0) {
+        pa_xfree(*parameter_list);
+        *parameter_list = NULL;
+        return PA_PARAM_PARSE_ERROR;
+    }
+
+    return element_count;
+}
+
+/* Converts a parameter list to an int64 array. */
+int pa_message_param_read_int64_array(char *c, int64_t **parameter_list) {
+    int64_t  value;
+    void *state = NULL;
+    uint32_t element_count, i;
+    int err;
+
+    pa_assert(parameter_list);
+
+    *parameter_list = NULL;
+
+    /* Count elements, return if no element was found or parse error. */
+    if ((element_count = count_elements(c)) <= 0)
+        return element_count;
+
+    /* Allocate array */
+    *parameter_list = pa_xmalloc(element_count * sizeof(int64_t));
+
+    i = 0;
+    while ((err = pa_message_param_read_int64(c, &value, &state)) > 0) {
+       (*parameter_list)[i] = value;
+        i++;
+    }
+
+    if (err < 0) {
+        pa_xfree(*parameter_list);
+        *parameter_list = NULL;
+        return PA_PARAM_PARSE_ERROR;
+    }
+
+    return element_count;
+}
+
+/* Converts a parameter list to an uint64 array. */
+int pa_message_param_read_uint64_array(char *c, uint64_t **parameter_list) {
+    uint64_t  value;
+    void *state = NULL;
+    uint32_t element_count, i;
+    int err;
+
+    pa_assert(parameter_list);
+
+    *parameter_list = NULL;
+
+    /* Count elements, return if no element was found or parse error. */
+    if ((element_count = count_elements(c)) <= 0)
+        return element_count;
+
+    /* Allocate array */
+    *parameter_list = pa_xmalloc(element_count * sizeof(uint64_t));
+
+    i = 0;
+    while ((err = pa_message_param_read_uint64(c, &value, &state)) > 0) {
+       (*parameter_list)[i] = value;
+        i++;
+    }
+
+    if (err < 0) {
+        pa_xfree(*parameter_list);
+        *parameter_list = NULL;
+        return PA_PARAM_PARSE_ERROR;
+    }
+
+    return element_count;
+}
+
 /* Write functions. The functions are wrapper functions around pa_strbuf,
  * so that the client does not need to use pa_strbuf directly. */
 
diff --git a/src/pulse/message-params.h b/src/pulse/message-params.h
index f865e236..3ab1e418 100644
--- a/src/pulse/message-params.h
+++ b/src/pulse/message-params.h
@@ -60,6 +60,18 @@ int pa_message_param_read_uint64(char *c, uint64_t *result, void **state);
 /** Read a boolean from the parameter list. */
 int pa_message_param_read_bool(char *c, bool *result, void **state);
 
+/** Convert message parameter list to string array */
+int pa_message_param_read_string_array(char *c, char ***parameter_list, bool allocate);
+
+/** Convert message parameter list to double array */
+int pa_message_param_read_double_array(char *c, double **parameter_list);
+
+/** Convert message parameter list to int64 array */
+int pa_message_param_read_int64_array(char *c, int64_t **parameter_list);
+
+/** Convert message parameter list to uint64 array */
+int pa_message_param_read_uint64_array(char *c, uint64_t **parameter_list);
+
 /** Write functions */
 
 /** Create a new pa_message_param structure */
-- 
2.14.1



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