Add new skpinfo tool

tools/skpinfo.cpp

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCommandLineFlags.h"
+#include "SkPicture.h"
+#include "SkPicturePlayback.h"
+#include "SkStream.h"
+
+DEFINE_string2(input, i, "", "skp on which to report");
+DEFINE_bool2(version, v, true, "version");
+DEFINE_bool2(width, w, true, "width");
+DEFINE_bool2(height, h, true, "height");
+DEFINE_bool2(tags, t, true, "tags");
+DEFINE_bool2(quiet, q, false, "quiet");
+
+// This tool can print simple information about an SKP but its main use
+// is just to check if an SKP has been truncated during the recording
+// process.
+// return codes:
+static const int kSuccess = 0;
+static const int kTruncatedFile = 1;
+static const int kNotAnSKP = 2;
+static const int kInvalidTag = 3;
+static const int kMissingInput = 4;
+static const int kIOError = 5;
+
+int tool_main(int argc, char** argv);
+int tool_main(int argc, char** argv) {
+    SkCommandLineFlags::SetUsage("Prints information about an skp file");
+    SkCommandLineFlags::Parse(argc, argv);
+
+    if (FLAGS_input.count() != 1) {
+        if (!FLAGS_quiet) {
+            SkDebugf("Missing input file\n");
+        }
+        return kMissingInput;
+    }
+
+    SkFILEStream* stream = SkNEW_ARGS(SkFILEStream, (FLAGS_input[0]));

[mtklein, 2014/03/03 16:27:37]

Sorry if I wasn't clear, I think you really do want
  SkFILEStream stream(FLAGS_input[0]);
There's no reason to heap allocate this stream, and despite it not really
mattering it seems bad form to leak it, particularly when FILEs are involved.

[robertphillips, 2014/03/03 18:44:24]

Done.

+    if (!stream->isValid()) {
+        if (!FLAGS_quiet) {
+            SkDebugf("Couldn't open file\n");
+        }
+        return kIOError;
+    }
+
+    size_t totStreamSize = stream->getLength();
+
+    SkPictInfo info;
+    if (!SkPicture::StreamIsSKP(stream, &info)) {
+        return kNotAnSKP;
+    }
+
+    if (FLAGS_version && !FLAGS_quiet) {
+        SkDebugf("Version: %d\n", info.fVersion);
+    }
+    if (FLAGS_width && !FLAGS_quiet) {
+        SkDebugf("Width: %d\n", info.fWidth);
+    }
+    if (FLAGS_height && !FLAGS_quiet) {
+        SkDebugf("Height: %d\n", info.fHeight);
+    }
+
+    if (!stream->readBool()) {
+        // If the read bool is false then we're done reading the file.

[mtklein, 2014/03/03 16:27:37]

I'm not really sure this comment says anything the code doesn't.  Maybe as you
explained it to me?

// If we read true there's a picture playback object flattened in the file; if
false, there isn't a playback, so we're done reading the file.

[robertphillips, 2014/03/03 18:44:24]

Done.

+        return kSuccess;
+    }
+
+    for (;;) {
+        uint32_t tag = stream->readU32();
+        if (SK_PICT_EOF_TAG == tag) {
+            break;
+        }
+
+        uint32_t chunkSize = stream->readU32();
+        size_t curPos = stream->getPosition();
+
+        // "move" doesn't error out when seeking beyond the end of file
+        // so we need a preemptive check here.
+        if (curPos+chunkSize > totStreamSize) {
+            if (!FLAGS_quiet) {
+                SkDebugf("truncated file\n");
+            }
+            return kTruncatedFile;
+        }
+
+        switch (tag) {
+        case SK_PICT_READER_TAG: 
+            if (FLAGS_tags && !FLAGS_quiet) {
+                SkDebugf("SK_PICT_READER_TAG %d\n", chunkSize);
+            }
+            break;
+        case SK_PICT_FACTORY_TAG:
+            if (FLAGS_tags && !FLAGS_quiet) {
+                SkDebugf("SK_PICT_FACTORY_TAG %d\n", chunkSize);
+                SkDebugf("Exiting early due to format limitations\n");
+            }
+            return kSuccess;       // TODO: need to store size in bytes
+            break;
+        case SK_PICT_TYPEFACE_TAG:
+            if (FLAGS_tags && !FLAGS_quiet) {
+                SkDebugf("SK_PICT_TYPEFACE_TAG %d\n", chunkSize);
+                SkDebugf("Exiting early due to format limitations\n");
+            }
+            return kSuccess;       // TODO: need to store size in bytes
+            break;
+        case SK_PICT_PICTURE_TAG:
+            if (FLAGS_tags && !FLAGS_quiet) {
+                SkDebugf("SK_PICT_PICTURE_TAG %d\n", chunkSize);
+                SkDebugf("Exiting early due to format limitations\n");
+            }
+            return kSuccess;       // TODO: need to store size in bytes
+            break;
+        case SK_PICT_BUFFER_SIZE_TAG:
+            if (FLAGS_tags && !FLAGS_quiet) {
+                SkDebugf("SK_PICT_BUFFER_SIZE_TAG %d\n", chunkSize);
+            }
+            break;
+        default:
+            if (!FLAGS_quiet) {
+                SkDebugf("Unknown tag %d\n", chunkSize);
+            }
+            return kInvalidTag;
+        }
+
+        if (!stream->move(chunkSize)) {
+            if (!FLAGS_quiet) {
+                SkDebugf("seek error\n");
+            }
+            return kTruncatedFile;
+        }
+    }
+
+    return kSuccess;
+}
+
+#if !defined SK_BUILD_FOR_IOS
+int main(int argc, char * const argv[]) {
+    return tool_main(argc, (char**) argv);
+}
+#endif