Subject: Re: [PATCH 15/23] http.c: new functions for the http API

From: Jakub Narebski <[email-masked]>
Date: Fri, 05 Jun 2009 13:50:00 -0700 (PDT)

Tay Ray Chuan <[email-masked]> writes:

> From:	Mike Hommey <[email-masked]>
> Subject: [WIP Patch 03/12] Two new functions for the http API

So what is the title of this patch: 
  "http.c: new functions for the http API"
or
  "Two new functions for the http API"

Or perhaps it better be
  "http.c: Add http_get_strbuf() and http_get_file() to http API"

> Date:	Sun, 18 Jan 2009 09:04:28 +0100
> 
> http_get_strbuf and http_get_file allow respectively to retrieve contents of
> an URL to a strbuf or an opened file handle.
> 
> http_error prints out an error message containing the URL and the curl error
> (in curl_errorstr).
> 
> Signed-off-by: Mike Hommey <[email-masked]>
> Signed-off-by: Tay Ray Chuan <[email-masked]>
> ---
> 
> I've added an additional slot->local = NULL when cleaning up in
> http_request().
> 
>  http.c |  104 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  http.h |   30 ++++++++++++++++++
>  2 files changed, 134 insertions(+), 0 deletions(-)
> 
> diff --git a/http.c b/http.c
> index 75fce9e..df22180 100644
> --- a/http.c
> +++ b/http.c
> @@ -665,6 +665,110 @@ static char *quote_ref_url(const char *base, const char *ref)
>  	return strbuf_detach(&buf, NULL);
>  }
> 
> +/* http_request() targets */
> +#define HTTP_REQUEST_STRBUF	0
> +#define HTTP_REQUEST_FILE	1
> +
> +static int http_request(const char *url, void *result, int target, int options)
> +{
> +	struct active_request_slot *slot;
> +	struct slot_results results;
> +	struct curl_slist *headers = NULL;
> +	struct strbuf buf = STRBUF_INIT;
> +	int ret;
> +
> +	slot = get_active_slot();
> +	slot->results = &results;
> +	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
> +
> +	if (result == NULL) {
> +		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
> +	} else {
> +		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
> +		curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
> +
> +		if (target == HTTP_REQUEST_FILE) {
> +			long posn = ftell(result);
> +			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
> +					 fwrite);
> +			if (posn > 0) {
> +				strbuf_addf(&buf, "Range: bytes=%ld-", posn);
> +				headers = curl_slist_append(headers, buf.buf);
> +				strbuf_reset(&buf);
> +			}
> +			slot->local = result;
> +		} else
> +			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
> +					 fwrite_buffer);
> +	}
> +
> +	strbuf_addstr(&buf, "Pragma:");
> +	if (options & HTTP_NO_CACHE)
> +		strbuf_addstr(&buf, " no-cache");
> +
> +	headers = curl_slist_append(headers, buf.buf);
> +
> +	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
> +	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
> +
> +	if (start_active_slot(slot)) {
> +		run_active_slot(slot);
> +		if (results.curl_result == CURLE_OK)
> +			ret = HTTP_OK;
> +		else if (missing_target(&results))
> +			ret = HTTP_MISSING_TARGET;
> +		else
> +			ret = HTTP_ERROR;
> +	} else {
> +		error("Unable to start HTTP request for %s", url);
> +		ret = HTTP_START_FAILED;
> +	}
> +
> +	slot->local = NULL;
> +	curl_slist_free_all(headers);
> +	strbuf_release(&buf);
> +
> +	return ret;
> +}
> +
> +int http_get_strbuf(const char *url, struct strbuf *result, int options)
> +{
> +	return http_request(url, result, HTTP_REQUEST_STRBUF, options);
> +}
> +
> +int http_get_file(const char *url, const char *filename, int options)
> +{
> +	int ret;
> +	struct strbuf tmpfile = STRBUF_INIT;
> +	FILE *result;
> +
> +	strbuf_addf(&tmpfile, "%s.temp", filename);
> +	result = fopen(tmpfile.buf, "a");
> +	if (! result) {
> +		error("Unable to open local file %s", tmpfile.buf);
> +		ret = HTTP_ERROR;
> +		goto cleanup;
> +	}
> +
> +	ret = http_request(url, result, HTTP_REQUEST_FILE, options);
> +	fclose(result);
> +
> +	if ((ret == HTTP_OK) && move_temp_to_file(tmpfile.buf, filename))
> +		ret = HTTP_ERROR;
> +cleanup:
> +	strbuf_release(&tmpfile);
> +	return ret;
> +}
> +
> +int http_error(const char *url, int ret)
> +{
> +	/* http_request has already handled HTTP_START_FAILED. */
> +	if (ret != HTTP_START_FAILED)
> +		error("%s while accessing %s\n", curl_errorstr, url);
> +
> +	return ret;
> +}
> +
>  int http_fetch_ref(const char *base, struct ref *ref)
>  {
>  	char *url;
> diff --git a/http.h b/http.h
> index 1ef7dc1..3d878d5 100644
> --- a/http.h
> +++ b/http.h
> @@ -114,6 +114,36 @@ static inline int missing__target(int code, int result)
> 
>  #define missing_target(a) missing__target((a)->http_code, (a)->curl_result)
> 
> +/* Options for http_request_*() */
> +#define HTTP_NO_CACHE		1
> +
> +/* Return values for http_request_*() */
> +#define HTTP_OK			0
> +#define HTTP_MISSING_TARGET	1
> +#define HTTP_ERROR		2
> +#define HTTP_START_FAILED	3
> +
> +/*
> + * Requests an url and stores the result in a strbuf.
> + *
> + * If the result pointer is NULL, a HTTP HEAD request is made instead of GET.
> + */
> +int http_get_strbuf(const char *url, struct strbuf *result, int options);
> +
> +/*
> + * Downloads an url and stores the result in the given file.
> + *
> + * If a previous interrupted download is detected (i.e. a previous temporary
> + * file is still around) the download is resumed.
> + */
> +int http_get_file(const char *url, const char *filename, int options);
> +
> +/*
> + * Prints an error message using error() containing url and curl_errorstr,
> + * and returns ret.
> + */
> +int http_error(const char *url, int ret);
> +
>  extern int http_fetch_ref(const char *base, struct ref *ref);
> 
>  #endif /* HTTP_H */
> --
> 1.6.3.1
> 

-- 
Jakub Narebski
Poland
ShadeHawk on #git