Add plist_read_from_file() to interface, update plist_from_memory()

plist_read_from_file() is a convenience function that will open a
given file, checks its size, allocates a buffer large enough to
hold the full contents, and reads from file to fill the buffer.
Then, it calls plist_from_memory() to convert the data to plist
format.
A (breaking) change had to be made so that plist_from_memory() will
also return the parsed format in its 4th argument (if non-NULL).

include/plist/plist.h

@@ -44,6 +44,7 @@ extern "C"
 #include <stdint.h>
 #endif
 
+/*{{{ deprecation macros */
 #ifdef __llvm__
   #if defined(__has_extension)
     #if (__has_extension(attribute_deprecated_with_message))
@@ -72,6 +73,7 @@ extern "C"
   #define PLIST_WARN_DEPRECATED(x)
   #pragma message("WARNING: You need to implement DEPRECATED for this compiler")
 #endif
+/*}}}*/
 
 #include <sys/types.h>
 #include <stdarg.h>
@@ -819,7 +821,8 @@ extern "C"
 
     /**
      * Import the #plist_t structure from memory data.
-     * This method will look at the first bytes of plist_data
+     *
+     * This function will look at the first bytes of plist_data
      * to determine if plist_data contains a binary, JSON, OpenStep, or XML plist
      * and tries to parse the data in the appropriate format.
      * @note This is just a convenience function and the format detection is
@@ -831,9 +834,25 @@ extern "C"
      * @param plist_data A pointer to the memory buffer containing plist data.
      * @param length Length of the buffer to read.
      * @param plist A pointer to the imported plist.
+     * @param format If non-NULL, the #plist_format_t value pointed to will be set to the parsed format.
      * @return PLIST_ERR_SUCCESS on success or a #plist_err_t on failure
      */
-    plist_err_t plist_from_memory(const char *plist_data, uint32_t length, plist_t * plist);
+    plist_err_t plist_from_memory(const char *plist_data, uint32_t length, plist_t *plist, plist_format_t *format);
+
+    /**
+     * Import the #plist_t structure directly from file.
+     *
+     * This function will look at the first bytes of the file data
+     * to determine if it contains a binary, JSON, OpenStep, or XML plist
+     * and tries to parse the data in the appropriate format.
+     * Uses #plist_read_from_data() internally.
+     *
+     * @param filename The name of the file to parse.
+     * @param plist A pointer to the imported plist.
+     * @param format If non-NULL, the #plist_format_t value pointed to will be set to the parsed format.
+     * @return PLIST_ERR_SUCCESS on success or a #plist_err_t on failure
+     */
+    plist_err_t plist_read_from_file(const char *filename, plist_t *plist, plist_format_t *format);
 
     /**
      * Write the #plist_t structure to a NULL-terminated string using the given format and options.

src/plist.c

@@ -197,7 +197,7 @@ PLIST_API int plist_is_binary(const char *plist_data, uint32_t length)
 #define FIND_NEXT(blob, pos, len, chr) \
     while (pos < len && (blob[pos] != chr)) pos++;
 
-PLIST_API plist_err_t plist_from_memory(const char *plist_data, uint32_t length, plist_t * plist)
+PLIST_API plist_err_t plist_from_memory(const char *plist_data, uint32_t length, plist_t *plist, plist_format_t *format)
 {
     int res = -1;
     if (!plist) {
@@ -207,8 +207,11 @@ PLIST_API plist_err_t plist_from_memory(const char *plist_data, uint32_t length,
     if (!plist_data || length == 0) {
         return PLIST_ERR_INVALID_ARG;
     }
+    plist_format_t fmt = 0;
+    if (format) *format = 0;
     if (plist_is_binary(plist_data, length)) {
         res = plist_from_bin(plist_data, length, plist);
+        fmt = PLIST_FORMAT_BINARY;
     } else {
         uint32_t pos = 0;
         int is_json = 0;
@@ -248,12 +251,59 @@ PLIST_API plist_err_t plist_from_memory(const char *plist_data, uint32_t length,
         }
         if (is_xml) {
             res = plist_from_xml(plist_data, length, plist);
+            fmt = PLIST_FORMAT_XML;
         } else if (is_json) {
             res = plist_from_json(plist_data, length, plist);
+            fmt = PLIST_FORMAT_JSON;
         } else {
             res = plist_from_openstep(plist_data, length, plist);
+            fmt = PLIST_FORMAT_OSTEP;
         }
     }
+    if (format && res == PLIST_ERR_SUCCESS) {
+        *format = fmt;
+    }
+    return res;
+}
+
+PLIST_API plist_err_t plist_read_from_file(const char *filename, plist_t *plist, plist_format_t *format)
+{
+    if (!filename || !plist) {
+        return PLIST_ERR_INVALID_ARG;
+    }
+    FILE *f = fopen(filename, "rb");
+    if (!f) {
+        return PLIST_ERR_IO;
+    }
+    struct stat fst;
+    fstat(fileno(f), &fst);
+    if (fst.st_size > UINT32_MAX) {
+        return PLIST_ERR_NO_MEM;
+    }
+    uint32_t total = (uint32_t)fst.st_size;
+    if (total == 0) {
+        return PLIST_ERR_PARSE;
+    }
+    char *buf = malloc(total);
+    if (!buf) {
+        fclose(f);
+        return PLIST_ERR_NO_MEM;
+    }
+    uint32_t done = 0;
+    while (done < total) {
+        ssize_t r = fread(buf + done, 1, total - done, f);
+        if (r <= 0) {
+            break;
+        }
+        done += r;
+    }
+    fclose(f);
+    if (done < total) {
+        free(buf);
+        return PLIST_ERR_IO;
+    }
+    plist_err_t res = plist_from_memory(buf, total, plist, format);
+    free(buf);
     return res;
 }
 

test/plist_cmp.c

@@ -75,21 +75,12 @@ static char compare_plist(plist_t node_l, plist_t node_r)
 
 int main(int argc, char *argv[])
 {
-    FILE *iplist1 = NULL;
-    FILE *iplist2 = NULL;
     plist_t root_node1 = NULL;
     plist_t root_node2 = NULL;
-    char *plist_1 = NULL;
-    char *plist_2 = NULL;
-    int size_in1 = 0;
-    int size_in2 = 0;
     char *file_in1 = NULL;
     char *file_in2 = NULL;
     int res = 0;
 
-    struct stat *filestats1 = (struct stat *) malloc(sizeof(struct stat));
-    struct stat *filestats2 = (struct stat *) malloc(sizeof(struct stat));
-
     if (argc!= 3)
     {
         printf("Wrong input\n");
@@ -99,36 +90,8 @@ int main(int argc, char *argv[])
     file_in1 = argv[1];
     file_in2 = argv[2];
 
-    //read input file
-    iplist1 = fopen(file_in1, "rb");
-    iplist2 = fopen(file_in2, "rb");
-
-    if (!iplist1 || !iplist2)
-    {
-        printf("File does not exists\n");
-        return 2;
-    }
-
-    stat(file_in1, filestats1);
-    stat(file_in2, filestats2);
-
-    size_in1 = filestats1->st_size;
-    size_in2 = filestats2->st_size;
-
-    plist_1 = (char *) malloc(sizeof(char) * (size_in1 + 1));
-    plist_2 = (char *) malloc(sizeof(char) * (size_in2 + 1));
-
-    fread(plist_1, sizeof(char), size_in1, iplist1);
-    fread(plist_2, sizeof(char), size_in2, iplist2);
-
-    fclose(iplist1);
-    fclose(iplist2);
-
-    plist_1[size_in1] = '\0';
-    plist_2[size_in2] = '\0';
-
-    plist_from_memory(plist_1, size_in1, &root_node1);
-    plist_from_memory(plist_2, size_in2, &root_node2);
+    plist_read_from_file(file_in1, &root_node1, NULL);
+    plist_read_from_file(file_in2, &root_node2, NULL);
 
     if (!root_node1 || !root_node2)
     {
@@ -142,11 +105,6 @@ int main(int argc, char *argv[])
     plist_free(root_node1);
     plist_free(root_node2);
 
-    free(plist_1);
-    free(plist_2);
-    free(filestats1);
-    free(filestats2);
-
     return !res;
 }
 

tools/plistutil.c

@@ -284,7 +284,7 @@ int main(int argc, char *argv[])
     }
     else
     {
-        input_res = plist_from_memory(plist_entire, read_size, &root_node);
+        input_res = plist_from_memory(plist_entire, read_size, &root_node, NULL);
         if (input_res == PLIST_ERR_SUCCESS) {
             if (options->flags & OPT_SORT) {
                 plist_sort(root_node);