fixed rewind function in http.c

.gitignore

@@ -1,3 +1,4 @@
 tmp
 *.o
 mount-http-dir
+*_test.txt

Makefile

@@ -1,7 +1,7 @@
 CC=gcc
-CFLAGS=-I. -Wall -Wextra -lgumbo -g
+CFLAGS=-I. -Wall -Wextra -lgumbo -lcurl -g
 DEPS =
-OBJ = main.o link.o test.o
+OBJ = main.o link.o test.o http.o
 
 %.o: %.c $(DEPS)
 	$(CC) -c -o $@ $< $(CFLAGS)

http.c

@@ -55,37 +55,9 @@
 #include <stdlib.h>
 #include <errno.h>
 
-#include <curl/curl.h>
+#include "http.h"
 
-enum fcurl_type_e {
-  CFTYPE_NONE = 0,
-  CFTYPE_FILE = 1,
-  CFTYPE_CURL = 2
-};
 
-struct fcurl_data
-{
-  enum fcurl_type_e type;     /* type of handle */
-  union {
-    CURL *curl;
-    FILE *file;
-  } handle;                   /* handle */
-
-  char *buffer;               /* buffer to store cached data*/
-  size_t buffer_len;          /* currently allocated buffers length */
-  size_t buffer_pos;          /* end of data in buffer*/
-  int still_running;          /* Is background url fetch still in progress */
-};
-
-typedef struct fcurl_data URL_FILE;
-
-/* exported functions */
-URL_FILE *url_fopen(const char *url, const char *operation);
-int url_fclose(URL_FILE *file);
-int url_feof(URL_FILE *file);
-size_t url_fread(void *ptr, size_t size, size_t nmemb, URL_FILE *file);
-char *url_fgets(char *ptr, size_t size, URL_FILE *file);
-void url_rewind(URL_FILE *file);
 
 /* we use a global one for convenience */
 static CURLM *multi_handle;
@@ -229,6 +201,26 @@ static int use_buffer(URL_FILE *file, size_t want)
   return 0;
 }
 
+static void http_curl_start_fetching(URL_FILE *file)
+{
+    /* lets start the fetch */
+    curl_multi_perform(multi_handle, &file->still_running);
+
+    if((file->buffer_pos == 0) && (!file->still_running)) {
+        /* if still_running is 0 now, we should return NULL */
+
+        /* make sure the easy handle is not in the multi handle anymore */
+        curl_multi_remove_handle(multi_handle, file->handle.curl);
+
+        /* cleanup */
+        curl_easy_cleanup(file->handle.curl);
+
+        free(file);
+
+        file = NULL;
+    }
+}
+
 URL_FILE *url_fopen(const char *url, const char *operation)
 {
   /* this code could check for URLs or types in the 'url' and
@@ -259,22 +251,7 @@ URL_FILE *url_fopen(const char *url, const char *operation)
 
     curl_multi_add_handle(multi_handle, file->handle.curl);
 
-    /* lets start the fetch */
-    curl_multi_perform(multi_handle, &file->still_running);
-
-    if((file->buffer_pos == 0) && (!file->still_running)) {
-      /* if still_running is 0 now, we should return NULL */
-
-      /* make sure the easy handle is not in the multi handle anymore */
-      curl_multi_remove_handle(multi_handle, file->handle.curl);
-
-      /* cleanup */
-      curl_easy_cleanup(file->handle.curl);
-
-      free(file);
-
-      file = NULL;
-    }
+    http_curl_start_fetching(file);
   }
   return file;
 }
@@ -438,6 +415,8 @@ void url_rewind(URL_FILE *file)
     file->buffer_pos = 0;
     file->buffer_len = 0;
 
+    http_curl_start_fetching(file);
+
     break;
 
   default: /* unknown or supported type - oh dear */
@@ -445,102 +424,3 @@ void url_rewind(URL_FILE *file)
   }
 }
 
-#define FGETSFILE "fgets.test"
-#define FREADFILE "fread.test"
-#define REWINDFILE "rewind.test"
-
-/* Small main program to retrieve from a url using fgets and fread saving the
- * output to two test files (note the fgets method will corrupt binary files if
- * they contain 0 chars */
-int main(int argc, char *argv[])
-{
-  URL_FILE *handle;
-  FILE *outf;
-
-  size_t nread;
-  char buffer[256];
-  const char *url;
-
-  if(argc < 2)
-    url = "http://192.168.7.3/testfile";/* default to testurl */
-  else
-    url = argv[1];/* use passed url */
-
-  /* copy from url line by line with fgets */
-  outf = fopen(FGETSFILE, "wb+");
-  if(!outf) {
-    perror("couldn't open fgets output file\n");
-    return 1;
-  }
-
-  handle = url_fopen(url, "r");
-  if(!handle) {
-    printf("couldn't url_fopen() %s\n", url);
-    fclose(outf);
-    return 2;
-  }
-
-  while(!url_feof(handle)) {
-    url_fgets(buffer, sizeof(buffer), handle);
-    fwrite(buffer, 1, strlen(buffer), outf);
-  }
-
-  url_fclose(handle);
-
-  fclose(outf);
-
-
-  /* Copy from url with fread */
-  outf = fopen(FREADFILE, "wb+");
-  if(!outf) {
-    perror("couldn't open fread output file\n");
-    return 1;
-  }
-
-  handle = url_fopen("testfile", "r");
-  if(!handle) {
-    printf("couldn't url_fopen() testfile\n");
-    fclose(outf);
-    return 2;
-  }
-
-  do {
-    nread = url_fread(buffer, 1, sizeof(buffer), handle);
-    fwrite(buffer, 1, nread, outf);
-  } while(nread);
-
-  url_fclose(handle);
-
-  fclose(outf);
-
-
-  /* Test rewind */
-  outf = fopen(REWINDFILE, "wb+");
-  if(!outf) {
-    perror("couldn't open fread output file\n");
-    return 1;
-  }
-
-  handle = url_fopen("testfile", "r");
-  if(!handle) {
-    printf("couldn't url_fopen() testfile\n");
-    fclose(outf);
-    return 2;
-  }
-
-  nread = url_fread(buffer, 1, sizeof(buffer), handle);
-  fwrite(buffer, 1, nread, outf);
-  url_rewind(handle);
-
-  buffer[0]='\n';
-  fwrite(buffer, 1, 1, outf);
-
-  nread = url_fread(buffer, 1, sizeof(buffer), handle);
-  fwrite(buffer, 1, nread, outf);
-
-  url_fclose(handle);
-
-  fclose(outf);
-
-  return 0;/* all done */
-}

http.h

@@ -1,9 +1,38 @@
 #ifndef HTTP_H
 #define HTTP_H
+
+#include <curl/curl.h>
+
+enum fcurl_type_e {
+    CFTYPE_NONE = 0,
+    CFTYPE_FILE = 1,
+    CFTYPE_CURL = 2
+};
+
+typedef struct {
+    enum fcurl_type_e type;     /* type of handle */
+    union {
+        CURL *curl;
+        FILE *file;
+    } handle;                   /* handle */
+
+    char *buffer;               /* buffer to store cached data*/
+    size_t buffer_len;          /* currently allocated buffers length */
+    size_t buffer_pos;          /* end of data in buffer*/
+    int still_running;          /* Is background url fetch still in progress */
+} URL_FILE;
+
 URL_FILE *url_fopen(const char *url, const char *operation);
+
 int url_fclose(URL_FILE *file);
+
 int url_feof(URL_FILE *file);
+
 size_t url_fread(void *ptr, size_t size, size_t nmemb, URL_FILE *file);
+
+/* \details This is probably not the function that you want to use! */
 char *url_fgets(char *ptr, size_t size, URL_FILE *file);
+
 void url_rewind(URL_FILE *file);
+
 #endif

main.c

@@ -7,7 +7,8 @@
 
 
 int main(int argc, char** argv) {
-    gumbo_test(argc, argv);
-    url_test();
+//     gumbo_test(argc, argv);
+//     url_test();
+    http_test();
     return 0;
 }

test.c

@@ -5,7 +5,118 @@
 
 #include "link.h"
 #include "test.h"
+#include "http.h"
 
+
+int http_test()
+{
+    URL_FILE *handle;
+    FILE *outf;
+
+    size_t nread;
+    char buffer[256];
+    const char *url;
+
+    url = "http://127.0.0.1/~fangfufu/test.txt";
+
+    /* ---------------------------Test fgets ----------------------------*/
+
+    /* open the input file */
+    handle = url_fopen(url, "r");
+    if(!handle) {
+        printf("couldn't url_fopen() %s\n", url);
+        return 2;
+    }
+
+    /* create the output file for fgets*/
+    outf = fopen("fgets_test.txt", "wb");
+    if(!outf) {
+        perror("couldn't open output file\n");
+        return 1;
+    }
+
+    /* copy from url line by line with fgets */
+    while(!url_feof(handle)) {
+        url_fgets(buffer, sizeof(buffer), handle);
+        fwrite(buffer, 1, strlen(buffer), outf);
+    }
+
+    /* close the handles for the fgets test*/
+    url_fclose(handle);
+    fclose(outf);
+
+    /* ---------------------------Test fread ----------------------------*/
+
+
+    /* open the input file again */
+    handle = url_fopen(url, "r");
+    if(!handle) {
+        printf("couldn't url_fopen() testfile\n");
+        return 2;
+    }
+
+    /* create the output file for fread test*/
+    outf = fopen("fread_test.txt", "wb");
+    if(!outf) {
+        perror("couldn't open fread output file\n");
+        return 1;
+    }
+
+    /* Copy from url with fread */
+    do {
+        nread = url_fread(buffer, 1, sizeof(buffer), handle);
+        fwrite(buffer, 1, nread, outf);
+    } while(nread);
+
+    /* close the handles for the fgets test*/
+    url_fclose(handle);
+    fclose(outf);
+
+    /* ---------------------------Test rewind ----------------------------*/
+    /* open the input file again */
+    handle = url_fopen(url, "r");
+    if(!handle) {
+        printf("couldn't url_fopen() testfile\n");
+        return 2;
+    }
+
+    /* create the output file for rewind test*/
+    outf = fopen("rewind_test.txt", "wb");
+    if(!outf) {
+        perror("couldn't open fread output file\n");
+        return 1;
+    }
+
+    /* Copy from url with fread */
+    do {
+        nread = url_fread(buffer, 1, sizeof(buffer), handle);
+        fwrite(buffer, 1, nread, outf);
+    } while(nread);
+
+    url_rewind(handle);
+    fprintf(outf, "\n-------------------\n");
+
+    /*
+     * read the URL again after rewind:
+     *  - copy from url line by line with fgets
+     */
+    while(!url_feof(handle)) {
+        url_fgets(buffer, sizeof(buffer), handle);
+        fwrite(buffer, 1, strlen(buffer), outf);
+    }
+
+    buffer[0]='\n';
+    fwrite(buffer, 1, 1, outf);
+
+    nread = url_fread(buffer, 1, sizeof(buffer), handle);
+    fwrite(buffer, 1, nread, outf);
+
+    url_fclose(handle);
+
+    fclose(outf);
+
+    return 0;/* all done */
+}
 void url_test()
 {
     printf("--- start of url_test ---\n");

test.h

@@ -3,4 +3,7 @@
 void url_test();
 
 void gumbo_test(int argc, char **argv);
+
+int http_test();
+
 #endif