smugfs(4): new program

src/cmd/smugfs/download.c

@@ -0,0 +1,105 @@
+#include "a.h"
+
+typedef struct DEntry DEntry;
+struct DEntry
+{
+	CEntry ce;
+	HTTPHeader hdr;
+	char *tmpfile;
+	int fd;
+};
+
+static void
+dfree(CEntry *ce)
+{
+	DEntry *d;
+	
+	d = (DEntry*)ce;
+	if(d->tmpfile){
+		remove(d->tmpfile);
+		free(d->tmpfile);
+		close(d->fd);
+	}
+}
+
+static Cache *downloadcache;
+
+static char*
+parseurl(char *url, char **path)
+{
+	char *host, *p;
+	int len;
+
+	if(memcmp(url, "http://", 7) != 0)
+		return nil;
+	p = strchr(url+7, '/');
+	if(p == nil)
+		p = url+strlen(url);
+	len = p - (url+7);
+	host = emalloc(len+1);
+	memmove(host, url+7, len);
+	host[len] = 0;
+	if(*p == 0)
+		p = "/";
+	*path = p;
+	return host;
+}
+
+int
+download(char *url, HTTPHeader *hdr)
+{
+	DEntry *d;
+	char *host, *path;
+	char buf[] = "/var/tmp/smugfs.XXXXXX";
+	char *req;
+	int fd;
+	Fmt fmt;
+
+	if(downloadcache == nil)
+		downloadcache = newcache(sizeof(DEntry), 128, dfree);
+
+	host = parseurl(url, &path);
+	if(host == nil)
+		return -1;
+	
+	d = (DEntry*)cachelookup(downloadcache, url, 1);
+	if(d->tmpfile){
+		free(host);
+		*hdr = d->hdr;
+		return dup(d->fd, -1);
+	}
+	d->fd = -1;  // paranoia
+
+	if((fd = opentemp(buf, ORDWR|ORCLOSE)) < 0){
+		free(host);
+		return -1;
+	}
+
+	fmtstrinit(&fmt);
+	fmtprint(&fmt, "GET %s HTTP/1.0\r\n", path);
+	fmtprint(&fmt, "Host: %s\r\n", host);
+	fmtprint(&fmt, "User-Agent: " USER_AGENT "\r\n");
+	fmtprint(&fmt, "\r\n");
+	req = fmtstrflush(&fmt);
+	
+	fprint(2, "Get %s\n", url);
+
+	if(httptofile(&http, host, req, hdr, fd) < 0){
+		free(host);
+		free(req);
+		return -1;
+	}
+	free(host);
+	free(req);
+	d->tmpfile = estrdup(buf);
+	d->fd = dup(fd, -1);
+	d->hdr = *hdr;
+	return fd;
+}
+
+void
+downloadflush(char *substr)
+{
+	if(downloadcache)
+		cacheflush(downloadcache, substr);
+}