Add reader.blob().

README.rst

@@ -323,6 +323,24 @@ Example::
 	synth_body.synth();
   }
 
+.. _xreader.blob():
+
+BLOB xreader.blob()
+-------------------
+
+Return the file's contents as a BLOB. Invokes VCL failure if the most
+recent update check encountered an error.
+
+Example::
+
+  import blob;
+
+  # Set the backend response body to the hex-encoded contents of
+  # the file. Also works for resp.body in vcl_synth.
+  sub vcl_backend_error {
+	set beresp.body = blob.encode(HEX, blob=synth_body.blob());
+  }
+
 .. _reader.error():
 
 .. _xreader.error():

src/tests/blob.vtc

+# looks like -*- vcl -*-
+
+varnishtest "reader.blob()"
+
+shell {echo -n "foo bar baz quux" > ${tmpdir}/blob}
+
+varnish v1 -vcl {
+	import ${vmod_file};
+	import blob;
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		new rdr = file.reader("${tmpdir}/blob", ttl=0.1s);
+	}
+
+	sub vcl_recv {
+		set req.http.Blob = blob.encode(blob=rdr.blob());
+		return (synth(200));
+	}
+
+	sub vcl_synth {
+		set resp.http.Blob = req.http.Blob;
+		return (deliver);
+	}
+} -start
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 200
+	expect resp.http.Blob == "foo bar baz quux"
+} -run
+
+shell {echo -n "quux baz bar foo" > ${tmpdir}/blob}
+delay .1
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 200
+	expect resp.http.Blob == "quux baz bar foo"
+} -run
+
+shell {chmod a-r ${tmpdir}/blob}
+delay .1
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 503
+	expect resp.reason == "VCL failed"
+} -run
+
+logexpect l1 -v v1 -d 1 -g vxid -q "VCL_Error" {
+	expect 0 * Begin	req
+	expect * = VCL_Error	{^rdr\.blob\(\): vmod file failure: vcl1\.rdr: cannot open}
+	expect * = End
+} -run

src/vmod_file.c

@@ -55,6 +55,9 @@
 	snprintf((rdr)->errbuf, (rdr)->errlen, "vmod file failure: " fmt, \
 		 __VA_ARGS__)
 
+/* Other VMODs may check the result of .blob() for this value, see vrt.h */
+#define VMOD_FILE_BLOB_MAGIC 0x069392c4
+
 #define INIT_SLEEP_INTERVAL 0.001
 #define ERRMSG_LEN 128
 #define NO_ERR ("No error")
@@ -546,6 +549,40 @@ vmod_reader_synth(VRT_CTX, struct VPFX(file_reader) *rdr)
 	return;
 }
 
+VCL_BLOB
+vmod_reader_blob(VRT_CTX, struct VPFX(file_reader) *rdr)
+{
+	struct vrt_blob *blob;
+
+	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
+	CHECK_OBJ_NOTNULL(rdr, FILE_READER_MAGIC);
+	CHECK_OBJ_NOTNULL(rdr->info, FILE_INFO_MAGIC);
+
+	if (WS_ReserveSize(ctx->ws, sizeof(*blob)) == 0) {
+		VRT_fail(ctx, "%s.blob(): cannot reserve workspace",
+			 rdr->obj_name);
+		return (NULL);
+	}
+	blob = (struct vrt_blob *)WS_Front(ctx->ws);
+	blob->type = VMOD_FILE_BLOB_MAGIC;
+
+	AZ(pthread_rwlock_rdlock(&rdr->lock));
+	if (rdr->flags & RDR_ERROR) {
+		VRT_fail(ctx, "%s.blob(): %s", rdr->obj_name, rdr->errbuf);
+		AZ(pthread_rwlock_unlock(&rdr->lock));
+		AN(strcmp(rdr->errbuf, NO_ERR));
+		WS_Release(ctx->ws, 0);
+		return (NULL);
+	}
+
+	blob->blob = rdr->addr;
+	blob->len = rdr->info->len - 1;
+	AZ(pthread_rwlock_unlock(&rdr->lock));
+
+	WS_Release(ctx->ws, sizeof(*blob));
+	return (blob);
+}
+
 VCL_BOOL
 vmod_reader_error(VRT_CTX, struct VPFX(file_reader) *rdr)
 {

src/vmod_file.vcc

@@ -303,6 +303,21 @@ Example::
 	synth_body.synth();
   }
 
+$Method BLOB .blob()
+
+Return the file's contents as a BLOB. Invokes VCL failure if the most
+recent update check encountered an error.
+
+Example::
+
+  import blob;
+
+  # Set the backend response body to the hex-encoded contents of
+  # the file. Also works for resp.body in vcl_synth.
+  sub vcl_backend_error {
+	set beresp.body = blob.encode(HEX, blob=synth_body.blob());
+  }
+
 .. _reader.error():
 
 $Method BOOL .error()