From 031f3f8028835c935d1e75ebd136aaaefffea821 Mon Sep 17 00:00:00 2001 From: nulltoken Date: Sat, 7 Sep 2013 22:39:05 +0200 Subject: [PATCH] odb: Error when streaming in too [few|many] bytes --- include/git2/odb.h | 6 ++++ include/git2/odb_backend.h | 13 +++++++-- src/odb.c | 27 +++++++++++++++++ tests-clar/odb/streamwrite.c | 56 ++++++++++++++++++++++++++++++++++++ 4 files changed, 99 insertions(+), 3 deletions(-) create mode 100644 tests-clar/odb/streamwrite.c diff --git a/include/git2/odb.h b/include/git2/odb.h index 3e93a932c..e50a2a1c1 100644 --- a/include/git2/odb.h +++ b/include/git2/odb.h @@ -238,6 +238,9 @@ GIT_EXTERN(int) git_odb_open_wstream(git_odb_stream **out, git_odb *db, size_t s /** * Write to an odb stream * + * This method will fail as soon as the total number of + * received bytes exceeds the size declared with `git_odb_open_wstream()` + * * @param stream the stream * @param buffer the data to write * @param len the buffer's length @@ -251,6 +254,9 @@ GIT_EXTERN(int) git_odb_stream_write(git_odb_stream *stream, const char *buffer, * The object will take its final name and will be available to the * odb. * + * This method will fail if the total number of received bytes + * differs from the size declared with `git_odb_open_wstream()` + * * @param out pointer to store the resulting object's id * @param stream the stream * @return 0 on success; an error code otherwise diff --git a/include/git2/odb_backend.h b/include/git2/odb_backend.h index bafeec047..e558bbb1c 100644 --- a/include/git2/odb_backend.h +++ b/include/git2/odb_backend.h @@ -78,6 +78,9 @@ struct git_odb_stream { unsigned int mode; void *hash_ctx; + size_t declared_size; + size_t received_bytes; + /** * Write at most `len` bytes into `buffer` and advance the * stream. @@ -93,9 +96,13 @@ struct git_odb_stream { * Store the contents of the stream as an object with the id * specified in `oid`. * - * This method will *not* be invoked by libgit2 if the object pointed at - * by `oid` already exists in any backend. Libgit2 will however take care - * of properly disposing the stream through a call to `free()`. + * This method will *not* be invoked by libgit2 when: + * - the object pointed at by `oid` already exists in any backend. + * - the total number of received bytes differs from the size declared + * with `git_odb_open_wstream()` + * + * Libgit2 will however take care of properly disposing the stream through + * a call to `free()`. */ int (*finalize_write)(git_odb_stream *stream, const git_oid *oid); diff --git a/src/odb.c b/src/odb.c index dfb252178..2e6869547 100644 --- a/src/odb.c +++ b/src/odb.c @@ -888,17 +888,44 @@ int git_odb_open_wstream( hash_header(ctx, size, type); (*stream)->hash_ctx = ctx; + (*stream)->declared_size = size; + (*stream)->received_bytes = 0; + return error; } +static int git_odb_stream__invalid_length( + const git_odb_stream *stream, + const char *action) +{ + giterr_set(GITERR_ODB, + "Cannot %s - " + "Invalid length. %"PRIuZ" was expected. The " + "total size of the received chunks amounts to %"PRIuZ".", + action, stream->declared_size, stream->received_bytes); + + return -1; +} + int git_odb_stream_write(git_odb_stream *stream, const char *buffer, size_t len) { git_hash_update(stream->hash_ctx, buffer, len); + + stream->received_bytes += len; + + if (stream->received_bytes > stream->declared_size) + return git_odb_stream__invalid_length(stream, + "stream_write()"); + return stream->write(stream, buffer, len); } int git_odb_stream_finalize_write(git_oid *out, git_odb_stream *stream) { + if (stream->received_bytes != stream->declared_size) + return git_odb_stream__invalid_length(stream, + "stream_finalize_write()"); + git_hash_final(out, stream->hash_ctx); if (git_odb_exists(stream->backend->odb, out)) diff --git a/tests-clar/odb/streamwrite.c b/tests-clar/odb/streamwrite.c new file mode 100644 index 000000000..591a20040 --- /dev/null +++ b/tests-clar/odb/streamwrite.c @@ -0,0 +1,56 @@ +#include "clar_libgit2.h" +#include "git2/odb_backend.h" + +static git_repository *repo; +static git_odb *odb; +static git_odb_stream *stream; + +void test_odb_streamwrite__initialize(void) +{ + repo = cl_git_sandbox_init("testrepo.git"); + cl_git_pass(git_repository_odb(&odb, repo)); + + cl_git_pass(git_odb_open_wstream(&stream, odb, 14, GIT_OBJ_BLOB)); + cl_assert_equal_sz(14, stream->declared_size); +} + +void test_odb_streamwrite__cleanup(void) +{ + git_odb_stream_free(stream); + git_odb_free(odb); + cl_git_sandbox_cleanup(); +} + +void test_odb_streamwrite__can_accept_chunks(void) +{ + git_oid oid; + + cl_git_pass(git_odb_stream_write(stream, "deadbeef", 8)); + cl_assert_equal_sz(8, stream->received_bytes); + + cl_git_pass(git_odb_stream_write(stream, "deadbeef", 6)); + cl_assert_equal_sz(8 + 6, stream->received_bytes); + + cl_git_pass(git_odb_stream_finalize_write(&oid, stream)); +} + +void test_odb_streamwrite__can_detect_missing_bytes(void) +{ + git_oid oid; + + cl_git_pass(git_odb_stream_write(stream, "deadbeef", 8)); + cl_assert_equal_sz(8, stream->received_bytes); + + cl_git_pass(git_odb_stream_write(stream, "deadbeef", 4)); + cl_assert_equal_sz(8 + 4, stream->received_bytes); + + cl_git_fail(git_odb_stream_finalize_write(&oid, stream)); +} + +void test_odb_streamwrite__can_detect_additional_bytes(void) +{ + cl_git_pass(git_odb_stream_write(stream, "deadbeef", 8)); + cl_assert_equal_sz(8, stream->received_bytes); + + cl_git_fail(git_odb_stream_write(stream, "deadbeef", 7)); +}